Process for the carbonylation of ethylenically unsaturated compounds, novel carbonylation ligands and catalyst systems incorporating such ligands

ABSTRACT

A novel bidentate ligand of general formula (I) 
                         
is described together with a process for the carbonylation of ethylenically unsaturated compounds. The group X 1  may be defined as a univalent hydrocarbyl radical of up to 30 atoms containing at least one nitrogen atom having a pKb in dilute aqueous solution at 18° C. of between 4 and 14 wherein the said at least one nitrogen atom is separated from the Q 2  atom by between 1 and 3 carbon atoms. The group X 2  is defined as X 1 , X 3  or X 4  or represents a univalent radical of up to 30 atoms having at least one primary, secondary or aromatic ring carbon atom wherein each said univalent radical is joined via said at least one primary, secondary or aromatic ring carbon atom(s) respectively to the respective atom Q 2 . Q 1  and Q 2  each independently represent phosphorus, arsenic or antimony.

This application is a continuation of U.S. patent application Ser. No.13/520,523, filed on Jul. 3, 2012, which is a National Stage ofInternational Application No. PCT/GB2010/052214, filed on Dec. 29, 2010.

The present invention relates to a process for the carbonylation ofethylenically unsaturated compounds, with a co-reactant, particularlyalcohol or water to give alkoxy and hydroxy-carbonylation thereof, novelbidentate ligands and novel catalyst systems incorporating such ligands.The carbonylation of ethylenically unsaturated compounds using carbonmonoxide in the presence of an alcohol or water and a catalyst systemcomprising a group 6, 8, 9 or 10 metal, for example, palladium, and aphosphine ligand, for example an alkyl phosphine, cycloalkyl phosphine,aryl phosphine, pyridyl phosphine or bidentate phosphine, has beendescribed in numerous European patents and patent applications, forexample EP-A-0055875, EP-A-04489472, EP-A-0106379, EP-A-0235864,EP-A-0274795, EP-A-0499329, EP-A-0386833, EP-A-0441447, EP-A-0489472,EP-A-0282142, EP-A-0227160, EP-A-0495547 and EP-A-0495548. Inparticular, EP-A-0227160, EP-A-0495547 and EP-A-0495548 disclose thatbidentate phosphine ligands provide catalyst systems which enable highreaction rates to be achieved. C3 alkyl bridges between the phosphorusatoms are exemplified in EPO495548 together with tertiary butylsubstituents on the phosphorus.

WO96/19434 subsequently disclosed that a particular group of bidentatephosphine compounds with tertiary carbon groups but having an arylbridge could provide remarkably stable catalysts which require little orno replenishment; that use of such bidentate catalysts leads to reactionrates which are significantly higher than those previously disclosed inEPO495548; that little or no impurities are produced at highconversions; and that the product has a high selectivity for the acid orester product and gives no polymer.

WO 01/68583 discloses rates for the same process and tertiary carbonsubstituted ligands as WO 96/19434 when used for higher alkenes and whenin the presence of an externally added aprotic solvent.

WO 98/42717 discloses a modification to the bidentate phosphines used inEPO495548 wherein the tertiary carbon groups are utilised by one or bothphosphorus atoms being incorporated into an optionally substituted2-phospha-tricyclo[3.3.1.1{3,7}]decyl group or a derivative thereof inwhich one or more of the carbon atoms are replaced by heteroatoms(“2-PA” group). Asymmetric ligands are envisaged but not exemplified.The examples include a number of alkoxycarbonylations of ethene, propeneand some higher terminal and internal olefins using symmetrical PAgroups incorporating each phosphorus and substituting each adjacentcarbon in the PA groups so that the carbons joined to the phosphorus aretertiary. There are no examples of the use of secondary or primarycarbons joined to the phosphorus. Improved rates and improved yields forcarbonylation of internally unsaturated olefins are found when comparedto 1,3-bis(di-t-butylphosphino)propane.

WO 03/070370 extends the particular tertiary carbon phosphorussubstituent ligands taught in WO 98/42717 to bidentate phosphines having1, 2 substituted aryl bridges of the type disclosed in WO96/19434.

WO 04/103948 describes both the above types of ligand bridges as usefulfor butadiene carbonylation and WO 05/082830 describes a selection of WO04/103948 where the tertiary carbon substituents are different on therespective phosphorus atoms leading to improved reaction rate.

It is known that the use of primary, secondary and aromatic carbonsubstituents on the bidentate phosphorus ligands lead to no or polymerproducts in the carbonylation of certain ethylenically unsaturatedcompounds. The general process for the production of polyketone polymershas been known for many years. EP 121,965, EP 181,014 and EP 213,671describe processes which involve the use of a bidentate phosphine ligandwith a group VIII metal such as palladium and an acid having a pKa ofless than 6. U.S. Pat. No. 4,950,703 teaches that a preferred catalystcomposition for producing polyketone polymer uses palladium, a suitableacid and 1,3-bis(diphenylphosphine)propane or1,3-bis[di(2-methyoxyphenyl)phosphino]propane.

For instance U.S. Pat. No. 5,369,074 teaches that such aromatic groupsubstituted ligands as 1,2-bis-(diphenylphosphino)propane and alkylsubstituted bidentate ligands joined to the phosphorus via a —CH₂ groupgive a range of molecular weight polyketone polymer products in goodyield in the carbonylation of ethylene using carbon monoxide.

It is known from WO01/87899 that ligands with the cyclic groups known asphobanes, for example, 9-phosphabicyclononane, joined to the phosphorusvia a secondary carbon and with an alkylene bridge can give goodselectivity and non-polymer product in such carbonylation reactions. InWO 05/082830 an asymmetric bidentate phosphine ligand is disclosedhaving tertiary carbons on one phosphorus and the phobane secondarycarbons on the other phosphorus. Unsurprisingly, the reaction stillgives a good selectivity to the ester product.

Surprisingly, it has now been found that a certain group of aromaticbridged asymmetric bidentate ligands do not give polymer product usingthe above types of alkyl and aromatic group substituted bidentateligands when in combination with tertiary carbon substituents and thatthese ligands also display improved stability and activity incarbonylation reactions especially in the presence of weaker acids thanhas hitherto proved advantageous.

According to the first aspect of the present invention there is provideda novel bidentate ligand according to the claims.

Optionally, there may be up to 3 nitrogen atoms in the hydrocarbyl X¹ orX² radical of the ligand of the invention with the closest nitrogen atombeing separated from the Q² atom by 1-3, preferably, 1 or 2, morepreferably, 1 carbon atom(s). The nitrogen atom may be substituted byhydrogen, aryl, alkyl or fluoroalkyl. The nitrogen atom may beincorporated into a heterocyclic group which may be saturated,unsaturated or part unsaturated. The unsaturated heterocycle may bearomatic or non-aromatic. The heterocycle may have between 3 and 14 ringatoms, preferably between 5 or 10 ring atoms, most preferably, 5 or 6.The heterocyclic group may have between 1 and 3 nitrogen atoms in thering, preferably 1 or 2, most preferably, 1. The hydrocarbyl radical maybe linear, branched or may form ring structures wherein the nitrogenatom(s) may or may not be incorporated into the ring. These ringstructures may be monocyclic or polycyclic, saturated, unsaturated orpart unsaturated and if unsaturated may be aromatic or non-aromatic. Thecyclic ring structure preferably has between 1 and 3 rings, morepreferably 1 or 2 rings, most preferably 1 ring and may be heterocyclicwith the at least one nitrogen(s) in the ring structure ornon-heterocyclic with the said nitrogen(s) outside the ring structure.

Alternatively, the group X¹ may be defined as a univalent radical of upto 30 atoms represented by formula Ib(C¹R¹⁰¹R¹⁰²)_(y)(C²R¹⁰¹R¹⁰²R¹¹⁰)_(x)(NR¹⁰¹R¹⁰²)_(a)  (Ib)wherein C¹ is attached directly to Q² and at least one further atomselected from C² and N and y=1;wherein R¹⁰¹ and R¹⁰² represent optional substituents hydrogen, aryl,alkyl or fluoroalkyl when C¹, C² and/or N have 1 or 2 free substituentsites;wherein the or each C² atom is either attached directly to an N atom orindirectly to an N atom via another C² atom, and x is 0 to 6,preferably, 1 to 4, more preferably, 3 or 4;wherein the or each N is independently attached to C¹ or C² and a is 1,2 or 3, preferably, 1;R¹¹⁰ is hydrogen, aryl, alkyl or fluoroalkyl;wherein, when x is 1 or more, C² may form a cyclic structure of 3 ormore atoms which if x is 1 incorporates N and C¹, which if x is 2incorporates N and/or C¹ and if x is 3 optionally incorporates N and/orC¹.

Preferably, in the present invention, the pKb of the at least onenitrogen atom measured in dilute aqueous solution at 18° C. is between 6and 12, more preferably, between 7 and 10, most preferably, 7.5 to 9.5.Typically, where there is more than one nitrogen atom, each nitrogenatom may have a pKb as set out above and in the claims. However, it isnot essential for any 2^(nd) of further nitrogen to have a pKb between 4and 14.

Preferably, the carbon directly joined to the Q² atom in the X¹ radicalis a non-tertiary carbon atom. Typically, the said carbon is a cyclic,primary or secondary carbon atom, more typically, an aromatic or primarycarbon atom, especially an aromatic carbon atom.

Preferably, the group X¹ is independently selected from an aziridine,azirine, azetidine, azete, pyrrolidone, pyrrole, pyridine, piperidine,azepane, azepine, azocane, azocine imidazolidine, pyrazolidine,imidazole, benzimidazole, imidazoline, pyrazole, indazole, pyrazoline,pyrazine, pyrimidine, pyridazine, piperazine, hexahydro-pyrimidine,hexahydro-pyridazine, indole, isoindole, quinoline, isoquinoline,quinazoline, benzopyrazine, acridine or benzoquinoline radical.

More preferably, the group X¹ is independently selected from the groupconsisting of an aziridine, azirine, azete, pyrrolidone, pyrrole,pyridine, azepane, azepine, azocane, azocine, imidazolidine,pyrazolidine, benzimidazole, imidazoline, indazole, pyrazoline,hexahydro-pyrimidine, hexahydro-pyridazine, isoindole, quinazoline,benzopyrazine, acridine and benzoquinoline radical.

Advantageously, by introducing the groups X¹ and optionally X² to the Q²atom it has been found that a catalyst system utilising such ligands incarbonylation reactions has surprisingly improved stability over anequivalent system using tertiary carbon atoms joined to both Q¹ and Q².Typically, the turnover number (TON) (moles of metal/moles of product)and/or rate for the carbonylation reaction, especially, hydroxy- oralkoxy-carbonylation is improved.

X¹ in the invention may optionally exclude CH(R²)(R³) wherein R² and R³represent Het and Het represents azetidinyl, pyrrolidinyl, imidazolyl,indolyl, furanyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl,thiadiazolyl, triazolyl, oxatriazolyl, thiatriazolyl, pyridazinyl,morpholinyl, pyrimidinyl, pyrazinyl, quinolinyl, isoquinolinyl,piperidinyl, pyrazolyl and piperazinyl.

Preferably, the ligands of the invention are utilised in continuouscarbonylation reactions but batch reactions, particularly repeat batchreactions will also benefit.

Therefore, according to a second aspect of the present invention thereis provided a process for the carbonylation of ethylenically unsaturatedcompounds according to the claims.

Preferably, in the process of the invention the catalyst system alsoincludes an acid and said ligand is present in at least a 1:1 molarratio, more preferably, at least a 2:1 molar excess compared to saidmetal or said metal in said metal compound, and that said acid ispresent in at least a 1:1 molar ratio, more preferably a greater than2:1 molar excess compared to said ligand.

According to a third aspect of the present invention there is provided acatalyst system according to claim 15.

Preferably, in the third aspect, said ligand is present in at least a1:1 molar ratio, more preferably, at least a 2:1 molar excess comparedto said metal or said metal in said metal compound, and that said acidis present in at least a 1:1 molar ratio, more preferably a greater than2:1 molar excess compared to said ligand.

Suitably, all of components a) to c), when present, of the catalystsystem of the present invention can be added in situ to the reactionvessel wherein the carbonylation is to take place. Alternatively, thecomponents a) to c) can be added sequentially in any order to form thecatalyst system, or in some specified order, either directly into thevessel or outside the vessel and then added to the vessel. For instance,the acid component c) may first be added to the bidentate ligandcomponent b), to form a protonated ligand, and then the protonatedligand can be added to the metal or compound thereof (component a)) toform the catalyst system. Alternatively, the ligand component b) andmetal or compound thereof (component a)) can be mixed to form a chelatedmetal compound, and the acid (component c)) is then added.Alternatively, any two components can be reacted together to form anintermediate moiety which is then either added to the reaction vesseland the third component added, or is first reacted with the thirdcomponent and then added to the reaction vessel.

As such, the present invention is directed to a process and catalystsystem leading to surprising and unexpected advantages when using thecatalyst system in the carbonylation of ethylenically unsaturatedcompounds in combination with the ligands defined herein, and thealleviation or at least reduction of at least some of the disadvantagesof the prior art systems. In particular, the use of a catalyst system ofthe present invention leads to a potentially more stable system,increased reaction rates, improved turnover numbers in carbonylationreactions of ethylenically unsaturated compounds, potentially improvedselectivity, improved conversion and an avoidance of polymerisation.

It will be appreciated by those skilled in the art that the compounds offormula (I) mentioned herein may function as ligands that coordinatewith the Group 8, 9 or 10 metal or compound thereof to form thecatalytic compounds for use in the invention. Typically, the Group 8, 9or 10 metal or compound thereof coordinates to the one or morephosphorus, arsenic and/or antimony atoms of the compound of formula I.

Co-Reactant

The ratio (mol/mol) of ethylenically unsaturated compound andco-reactant in the reaction can vary between wide limits and suitablylies in the range of 10:1 to 1:500, preferably, 2:1 to 1:2. However, ifthe ethylenically unsaturated compound is a gas at the reactiontemperature it may be present at lower levels in the liquid phasereaction medium such as at a ratio to co-reactant of 1:20,000 to 1:10more preferably, 1:10,000 to 1:50, most preferably, 1:5000 to 1:500 Theco-reactant of the present invention may be any compound including waterhaving a mobile hydrogen atom, and capable of reacting as a nucleophilewith the ethylenically unsaturated compound under catalytic conditions.The chemical nature of the co-reactant determines the type of productformed. Possible co-reactants are carboxylic acids, water, alcohols,ammonia or amines, thiols, or a combination thereof.

If the co-reactant is a carboxylic acid the product is an anhydride. Foran alcohol co reactant, the product of the carbonylation is an ester.Similarly, the use of ammonia (NH₃) or a primary or secondary amineR⁸¹NH₂ or R⁸²R⁸³NH will produce an amide, and the use of a thiol R⁸¹SHwill produce a thioester.

In the above-defined co-reactants, R⁸¹ R⁸² and/or R⁸³ represent alkyl,alkenyl or aryl groups which may be unsubstituted or may be substitutedby one or more substituents selected from halo, cyano, nitro, OR¹⁹,OC(O)R²⁰, C(O)R²¹, C(O)OR²², NR²³R²⁴, C(O)NR²⁵R²⁶, SR²⁹, C(O)SR³⁰,C(S)NR²⁷R²⁸, aryl or Het, wherein R¹⁹ to R³⁰ are defined herein, and/orbe interrupted by one or more oxygen or sulphur atoms, or by silano ordialkylsilicon groups.

If ammonia or amines are employed, a small portion of co-reactants willreact with acid present in the reaction to form an amide and water.Therefore, in the case of ammonia or amine-co-reactants, water may begenerated in situ.

Preferred amine co-reactants have from 1 to 22, more preferably, 1 to 8carbon atoms per molecule, and diamine co-reactants preferably have 2 to22, more preferably 2 to 10 carbon atoms per molecule. The amines can becyclic, part-cyclic, acyclic, saturated or unsaturated (includingaromatic), unsubstituted or substituted by one or more substituentsselected from halo, cyano, nitro, OR¹⁹, OC(O)R²⁰, C(O)R²¹, C(O)OR²²,NR²³R²⁴, C(O)NR²⁵R²⁶, SR²⁹, C(O)SR³⁰, C(S)NR²⁷R²⁸, aryl, alkyl, Het,wherein R¹⁹ to R³⁰ are as defined herein and/or be interrupted by one ormore (preferably less than a total of 4) oxygen, nitrogen, sulphur,silicon atoms or by silano or dialkyl silicon groups or mixturesthereof.

The thiol co-reactants can be cyclic, part-cyclic, acyclic, saturated orunsaturated (including aromatic), unsubstituted or substituted by one ormore substituents selected from halo, cyano, nitro, OR¹⁹, OC(O)R²⁰,C(O)R²¹, C(O)OR²², NR²³R²⁴, C(O)NR²⁵R²⁶, SR²⁹, C(O)SR³⁰, C(S)NR²⁷R²⁸,aryl, alkyl, Het, wherein R¹⁹ to R³⁰ are as defined herein and/or beinterrupted by one or more (preferably less than a total of 4) oxygen,nitrogen, sulphur, silicon atoms or by silano or dialkyl silicon groupsor mixtures thereof. Preferred thiol co-reactants are aliphatic thiolswith 1 to 22, more preferably with 1 to 8 carbon atoms per molecule, andaliphatic di-thiols with 2 to 22, more preferably 2 to 8 carbon atomsper molecule.

If a co-reactant should react with the acid serving as a source ofanions, then the amount of the acid to co-reactant should be chosen suchthat a suitable amount of free acid is still present in the reaction. Alarge surplus of acid over the co-reactant may be advantageous due tothe enhanced reaction rates facilitated by the excess acid.

As mentioned above, the present invention provides a process for thecarbonylation of ethylenically unsaturated compounds comprisingcontacting an ethylenically unsaturated compound with carbon monoxideand a co-reactant. The co-reactant is more preferably an organicmolecule having an hydroxyl functional group such as an alkanol orwater.

Suitably, as mentioned above, the co-reactant includes an organicmolecule having an hydroxyl functional group. Preferably, the organicmolecule having a hydroxyl functional group may be branched or linear,cyclic, acyclic, part cyclic or aliphatic and is, typically an alkanol,particularly a C₁-C₃₀ alkanol, including aryl alcohols, which may beoptionally substituted with one or more substituents selected fromalkyl, aryl, Het, halo, cyano, nitro, OR¹⁹, OC(O)R²⁰, C(O)R²¹, C(O)OR²²,NR²³R²⁴, C(O)NR²⁵R²⁶, C(S)NR²⁷R²⁸, SR²⁹ or C(O)SR³⁰ as defined herein.Highly preferred alkanols are C₁-C₈ alkanols such as methanol, ethanol,propanol, iso-propanol, iso-butanol, t-butyl alcohol, phenol, n-butanoland chlorocapryl alcohol. Although the monoalkanols are most preferred,poly-alkanols, preferably, selected from di-octa ols such as diols,triols, tetra-ols and sugars may also be utilised. Typically, suchpolyalkanols are selected from 1,2-ethanediol, 1,3-propanediol,glycerol, 1,2,4 butanetriol, 2-(hydroxymethyl)-1,3-propanediol, 1,2,6trihydroxyhexane, pentaerythritol, 1,1,1 tri(hydroxymethyl)ethane,nannose, sorbase, galactose and other sugars. Preferred sugars includesucrose, fructose and glucose. Especially preferred alkanols aremethanol and ethanol. The most preferred alkanol is methanol. The amountof alcohol is not critical. Generally, amounts are used in excess of theamount of substrate to be carbonylated. Thus the alcohol may serve asthe reaction solvent as well, although, if desired, separate solventsmay also be used.

It will be appreciated that the end product of the reaction isdetermined at least in part by the source of alkanol used. For instance,use of methanol produces the corresponding methyl ester. If theco-reactant is water the product is the corresponding acid. Accordingly,the invention provides a convenient way of adding the group —C(O)OC₁-C₃₀ alkyl or aryl across the ethylenically unsaturated bond.

Solvents

Preferably, the reaction of the present invention is carried out in thepresence of a suitable solvent. Suitable solvents will be describedhereafter. Preferably, the group 8, 9 or 10 metal/metal compound andligand are added to the solvent(s) and preferably, dissolved therein.

Suitable solvents for use in the present invention include ketones, suchas for example methylbutylketone; ethers, such as for example anisole(methyl phenyl ether), 2,5,8-trioxanonane (diglyme), diethyl ether,dimethyl ether, methyl-tert-butylether (MTBE), tetrahydrofuran,diphenylether, diisopropylether and the dimethylether ofdi-ethylene-glycol; oxanes, such as for example dioxane; esters, such asfor example methylacetate, dimethyladipate methyl benzoate, dimethylphthalate and butyrolactone; amides, such as for exampledimethylacetamide, N-methylpyrrolidone and dimethyl formamide;sulfoxides and sulphones, such as for example dimethylsulphoxide,di-isopropylsulphone, sulfolane (tetrahydrothiophene-2,2-dioxide),2-methylsulfolane, diethyl sulphone, tetrahydrothiophene 1,1-dioxide and2-methyl-4-ethylsulfolane; aromatic compounds, including halo variantsof such compounds e.g. benzene, toluene, ethyl benzene o-xylene,m-xylene, p-xylene, chlorobenzene, o-dichlorobenzene, m-dichlorobenzene:alkanes, including halo variants of such compounds e.g. hexane, heptane,2,2,3-trimethylpentane, methylene chloride and carbon tetrachloride;nitriles e.g. benzonitrile and acetonitrile.

Very suitable are aprotic solvents having a dielectric constant that isbelow a value of 50, more preferably 1-30, most preferably, 1-10,especially in the range of 2 to 8, at 298 or 293K and 1×10⁵Nm⁻². In thecontext herein, the dielectric constant for a given co-solvent is usedin its normal meaning of representing the ratio of the capacity of acondenser with that substance as dielectric to the capacity of the samecondenser with a vacuum for dielectric. Values for the dielectricconstants of common organic liquids can be found in general referencebooks, such as the Handbook of Chemistry and Physics, 76^(th) edition,edited by David R. Lide et al, and published by CRC press in 1995, andare usually quoted for a temperature of about 20° C. or 25° C., i.e.about 293.15 k or 298.15 K, and atmospheric pressure, i.e. about1×10⁵Nm⁻², and can readily be converted to 298.15 K and atmosphericpressure using the conversion factors quoted. If no literature data fora particular compound is available, the dielectric constant may bereadily measured using established physico-chemical methods.

Measurement of a dielectric constant of a liquid can easily be performedby various sensors, such as immersion probes, flow-through probes, andcup-type probes, attached to various meters, such as those availablefrom the Brookhaven Instruments Corporation of Holtsville, N.Y. (e.g.,model BI-870) and the Scientifica Company of Princeton, N.J. (e.g.models 850 and 870). For consistency of comparison, preferably allmeasurements for a particular filter system are performed atsubstantially the same sample temperature, e.g., by use of a water bath.Generally, the measured dielectric constant of a substance will increaseat lower temperatures and decrease at higher temperatures. Thedielectric constants falling within any ranges herein, may be determinedin accordance with ASTM D924.

However, if there is doubt as to which technique to use to determine thedielectric constant a Scientifica Model 870 Dielectric Constant Meterwith a 1-200 ∈ range setting should be used.

For example, the dielectric constant of methyl-tert-butyl ether is 4.34(at 293 K), of dioxane is 2.21 (at 298 K), of toluene is 2.38 (at 298K), tetrahydrofuran is 7.5 (at 295.2 K) and of acetonitrile is 37.5 (at298 K). The dielectric values are taken from the handbook of chemistryand physics and the temperature of the measurement is given.

Alternatively, the reaction may proceed in the absence of an aproticsolvent not generated by the reaction itself. In other words, the onlyaprotic solvent is the reaction product. This aprotic solvent may besolely generated by the reaction itself or, more preferably, is added asa solvent initially and then also produced by the reaction itself.

Alternatively, a protic solvent or a source thereof may be used. Theprotic solvent may include a carboxylic acid (as defined above) or analcohol. Suitable protic solvents include the conventional proticsolvents known to the person skilled in the art, such as lower alcohols,such as, for example, methanol, ethanol and isopropanol, and primary andsecondary amines. Mixtures of the aprotic and protic co-solvents mayalso be employed both initially and when generated by the reactionitself.

By protic solvent is meant any solvent that carries a donatable hydrogenion such as those attached to oxygen as in a hydroxyl group or nitrogenas in an amine group. By aprotic solvent is meant a type of solventwhich neither donates nor accepts protons.

Metal

For the avoidance of doubt, references to Group 8, 9 or 10 metals hereinshould be taken to include Groups 8, 9 and 10 in the modern periodictable nomenclature. By the term “Group 8, 9 or 10” we preferably selectmetals such as Ru, Rh, Os, Ir, Pt and Pd. Preferably, the metals areselected from Ru, Pt and Pd, more preferably, the metal is Pd.

Anion

Suitable compounds of such Group 8, 9 or 10 metals include salts of suchmetals with, or compounds comprising weakly coordinated anions derivedfrom, nitric acid; sulphuric acid; lower alkanoic (up to C₁₂) acids suchas acetic acid and propionic acid; sulphonic acids such as methanesulphonic acid, chlorosulphonic acid, fluorosulphonic acid,trifluoromethane sulphonic acid, benzene sulphonic acid, naphthalenesulphonic acid, toluene sulphonic acid, e.g. p-toluene sulphonic acid,t-butyl sulphonic acid, and 2-hydroxypropane sulphonic acid; sulphonatedion exchange resins (including low acid level sulphonic resins) perhalicacid such as perchloric acid; halogenated carboxylic acids such astrichloroacetic acid and trifluoroacetic acid; orthophosphoric acid;phosphonic acids such as benzenephosphonic acid; and acids derived frominteractions between Lewis acids and Broensted acids. Other sourceswhich may provide suitable anions include the optionally halogenatedtetraphenyl borate derivatives, e.g. perfluorotetraphenyl borate.Additionally, zero valent palladium complexes particularly those withlabile ligands, e.g. triphenylphosphine or alkenes such asdibenzylideneacetone or styrene or tri(dibenzylideneacetone)dipalladiummay be used.

The above anions may be introduced directly as a compound of the metalbut may also be introduced to the catalyst system independently of themetal or metal compound. Preferably, they are introduced as the acid.Preferably, an acid is selected to have a pKa less than 6 measured indilute aqueous solution at 18° C. The pKa is preferably less than about5 measured in dilute aqueous solution at 18° C. Particularly preferredacids have a pKa of less than 2 measured in dilute aqueous solution at18° C. but, in the case of some substrates such as dienes, a pKa ofbetween 2-6 measured in dilute aqueous solution at 18° C. is preferred.Suitable acids and salts may be selected from the acids and salts listedsupra.

Accordingly, preferably, the catalyst system of the present inventionincludes a source of anions preferably derived from one or more acidshaving a pKa in aqueous solution at 18° C. of less than 6, morepreferably, less than 5, most preferably, less than 2.

Addition of such acids to the catalyst system is preferred and providesacidic reaction conditions.

For the avoidance of doubt, references to pKa herein are references topKa measured in dilute aqueous solution at 18° C. unless indicatedotherwise. For the purposes of the invention herein, the pKa may bedetermined by suitable techniques known to those skilled in the art.

In the carbonylation reaction the quantity of anion present is notcritical to the catalytic behaviour of the catalyst system. The molarratio of anion to Group 8, 9 or 10 metal or compound may be from 1:1 to10000:1, preferably from 10:1 to 2000:1 and particularly from 100:1 to1000:1. However, for a weak acid having a pKa in dilute aqueous solutionat 18° C. greater than 0, the molar ratio may be higher and from 1:1 to100,000:1, preferably, 500:1 to 500,000:1, more preferably, 1000:1 to10,000:1. Where the anion is provided by an acid and salt, the relativeproportion of the acid and salt is not critical. Accordingly, if aco-reactant should react with an acid serving as source of anions, thenthe amount of the acid to co-reactant should be chosen such that asuitable amount of free acid is present.

Advantageously, the ligands of the invention show surprisingly goodactivity with relatively weak acids having a pKa in dilute aqueoussolution at 18° C. greater than 0 and less than 6. For instance, theligands of the invention show good activity with trifluoroacetic acidand activity with propionic acid. In industrial processes thepossibility of activity in the presence of a relatively weak acid willbe advantageous due to lower corrosion of plant parts.

Carbonylating Agent and Process Conditions

In the process according to the present invention, the carbon monoxidemay be used in pure form or diluted with an inert gas such as nitrogen,carbon dioxide or a noble gas such as argon.

Hydrogen may optionally be added to the carbonylation reaction toimprove reaction rate. Suitable levels of hydrogen when utilised may bein the ratio of between 0.1 and 10% vol/vol of the carbon monoxide, morepreferably, 1-10% vol/vol of the carbon monoxide, more preferably, 2-5%vol/vol of the carbon monoxide, most preferably 3-5% vol/vol of carbonmonoxide.

The molar ratio of the amount of ethylenically unsaturated compound usedin the reaction to the amount of solvent is not critical and may varybetween wide limits, e.g. from 1:1 to 1000:1 mol/mol. Preferably, themolar ratio of the amount of ethylenically unsaturated compound used inthe reaction to the amount of solvent is between 1:2 and 1:500, morepreferably, 1:2 to 1:100. For the avoidance of doubt, such solventincludes the reaction product and co-reactant.

The amount of the catalyst of the invention used in the carbonylationreaction is not critical. Good results may be obtained, preferably whenthe amount of Group 8, 9 or 10 metal is in the range 1×10⁻⁷ to 10⁻¹moles per mole of ethylenically unsaturated compound, more preferably,1×10⁻⁶ to 10⁻¹ moles, most preferably 1×10⁻⁶ to 10⁻² moles per mole ofethylenically unsaturated compound.

Preferably, the amount of ligand of formula I to ethylenicallyunsaturated compound is in the range 1×10⁻⁶ to 10⁻¹, more preferably,1×10⁻⁵ to 10⁻¹, most preferably, 1×10⁻⁵ to 10⁻² moles per mole ofethylenically unsaturated compound. Preferably, the amount of catalystis sufficient to produce product at an acceptable rate commercially.

Preferably, the carbonylation is carried out at temperatures of between−30 to 170° C., more preferably −10° C. to 160° C., most preferably 20°C. to 150° C. An especially preferred temperature is one chosen between40° C. to 150° C. Alternatively, the carbonylation can be carried out atmoderate temperatures, it is particularly advantageous in somecircumstances to be able to carry out the reaction at or around roomtemperature (20° C.)

Preferably, when operating a low temperature carbonylation, thecarbonylation is carried out between −30° C. to 49° C., more preferably,−10° C. to 45° C., still more preferably 0° C. to 45° C., mostpreferably 10° C. to 45° C. Especially preferred is a range of 10 to 35°C.

Preferably, the carbonylation is carried out at a CO partial pressure inthe reactor of between 0.01×10⁵N·m⁻²-2×10⁵N·m⁻², more preferably0.02×10⁵ N·m⁻²-1×10⁵N·m⁻², most preferably 0.05−0.5×10⁵ N·m⁻².Especially preferred is a CO partial pressure of 0.1 to 0.3×10⁵N·m⁻².

In the continuous carbonylation reaction of the invention, preferably,the ratio of equivalents of bidentate ligand to group 8, 9 or 10 metalis at least 1:1 mol/mol. The ligand may be in excess of metal mol/molbut is especially between 1:1 and 2:1 mol/mol.

Preferably, generally, the mole ratio of ligand to group 8, 9 or 10metal for a bidentate ligand is between 1:1 and 100:1, more preferably,1:1 to 50:1, most preferably, 1:1 to 20:1. For a monodentate,tridentate, etc ligand the mole ratio is varied accordingly.

Preferably, the mole ratio of ligand to acid in the reactor for abidentate ligand and a monoprotic acid is at least 1:2 and may be up to1:25000. However, typically, for most applications, a range of 1:4 to1:5000, more typically, 1:10 to 1:2000 is sufficient. For a monodentate,tridentate, etc ligand and/or diprotic, or triprotic etc acid, the moleratio is varied accordingly.

Preferably, the acid is present in the catalyst system, or precursorthereto, in such quantity that the molar ratio of said acid to saidmetal is at least 4:1, more preferably from 4:1 to 100000:1, even morepreferably 10:1 to 75000:1, yet more preferably 20:1 to 50000:1, yetstill more preferably 25:1 to 50000:1, yet still more preferably 30:1 to50000:1, yet even more preferably 40:1 to 40000:1, still more preferably100:1 to 25000:1, yet still more preferably 200:1 to 25000:1, mostpreferably 550:1 to 20000:1, or greater than 2000:1 to 20000:1.Alternatively, the said ratio can be in the range 125:1 to 485:1, morepreferably 150:1 to 450:1, even more preferably 175:1 to 425:1, yet evenmore preferably 200:1 to 400:1, most preferably 225:1 to 375:1.

For a diprotic, triprotic, etc acid, the mole ratio is variedaccordingly.

For the avoidance of doubt, the above ratio conditions apply at thestart of a batch reaction or during a continuous reaction.

As mentioned, the catalyst system of the present invention may be usedhomogeneously or heterogeneously. Preferably, the catalyst system isused homogeneously.

Suitably, the catalysts of the invention are prepared in a separate steppreceding their use in-situ in the carbonylation reaction.

Conveniently, the process of the invention may be carried out bydissolving the Group 8, 9 or 10 metal or compound thereof as definedherein in a suitable solvent such as one of the alkanols or aproticsolvents previously described or a mixture thereof. A particularlypreferred solvent would be the product of the specific carbonylationreaction which may be mixed with other solvents or co-reactants.Subsequently, the admixed metal and solvent may be mixed with a compoundof formula I as defined herein.

The carbon monoxide may be used in the presence of other gases which areinert in the reaction. Examples of such gases include hydrogen,nitrogen, carbon dioxide and the noble gases such as argon.

The product of the reaction may be separated from the other componentsby any suitable means. However, it is an advantage of the presentprocess that significantly fewer by-products are formed thereby reducingthe need for further purification after the initial separation of theproduct as may be evidenced by the generally significantly higherselectivity. A further advantage is that the other components whichcontain the catalyst system which may be recycled and/or reused infurther reactions with minimal supplementation of fresh catalyst.

There is no particular restriction on the duration of the carbonylationexcept that carbonylation in a timescale which is commerciallyacceptable is obviously preferred. Carbonylation in a batch reaction maytake place in up to 48 hours, more typically, in up to 24 hours and mosttypically in up to 12 hours. Typically, carbonylation is for at least 5minutes, more typically, at least 30 minutes, most typically, at least 1hour. In a continuous reaction such time scales are obviously irrelevantand a continuous reaction can continue as long as the TON iscommercially acceptable before catalyst requires replenishment.Significantly, in the present invention, this time scale toreplenishment can be increased.

The catalyst system of the present invention is preferably constitutedin the liquid phase which may be formed by one or more of the reactantsor by the use of one or more solvents as defined herein.

Ethylenically Unsaturated Compounds

Suitably, the process of the invention may be used to catalyse thecarbonylation of ethylenically unsaturated compounds in the presence ofcarbon monoxide and a co-reactant, having a mobile hydrogen atom, and,optionally, a source of anions. The ligands of the invention yield asurprisingly high TON in carbonylation, particularly, monocarbonylationreactions. Consequently, the commercial viability of a carbonylationprocess will be increased by employing the process of the invention.

Advantageously, use of the catalyst system of the present invention inthe carbonylation of ethylenically unsaturated compounds etc also givesgood rates especially for alkoxycarbonylation.

By monocarbonylation is meant the combination of an ethylenicallyunsaturated moiety and a single carbon monoxide molecule to produce anew insertion carbonylation end product without further insertion of asecond or further ethylenically unsaturated compound. Accordingly, theend product of a monocarbonylation reaction cannot be a polymer oroligomer which are both derived from multiple carbon monoxide andethylenically unsaturated compound insertions into a growing molecule.However, if there is more than one double bond in the ethylenicallyunsaturated compound then each double bond may combine with a singlecarbon monoxide molecule to form a new species but further insertion ofa second or further ethylenically unsaturated compound will not takeplace and monocarbonylation should be understood accordingly.

References to ethylenically unsaturated compounds herein should be takento include any one or more unsaturated C—C bond(s) in a compound such asthose found in alkenes, alkynes, conjugated and unconjugated dienes,functional alkenes etc.

Suitable ethylenically unsaturated compounds for the invention areethylenically unsaturated compounds having from 2 to 50 carbon atoms permolecule, or mixtures thereof. Suitable ethylenically unsaturatedcompounds may have one or more isolated or conjugated unsaturated bondsper molecule. Preferred are compounds having from 2 to 20 carbon atoms,or mixtures thereof, yet more preferred are compounds having at most 18carbon atoms, yet more at most 16 carbon atoms, again more preferredcompounds have at most 10 carbon atoms. The ethylenically unsaturatedcompound may further comprise functional groups or heteroatoms, such asnitrogen, sulphur or oxide. Examples include carboxylic acids, esters ornitriles as functional groups. In a preferred group of processes, theethylenically unsaturated compound is an olefin or a mixture of olefins.Suitable ethylenically unsaturated compounds include acetylene, methylacetylene, propyl acetylene, 1,3-butadiene, ethylene, propylene,butylene, isobutylene, pentenes, pentene nitriles, alkyl pentenoatessuch as methyl 3-pentenoates, pentene acids (such as 2- and 3-pentenoicacid), heptenes, vinyl esters such as vinyl acetate, octenes, dodecenes.

Particularly preferred ethylenically unsaturated compounds are ethylene,vinyl acetate, 1,3-butadiene, alkyl pentenoates, pentenenitriles,pentene acids (such as 3 pentenoic acid), acetylene, heptenes, butylene,octenes, dodecenes and propylene.

Especially preferred ethylenically unsaturated compounds are ethylene,propylene, heptenes, octenes, dodecenes, vinyl acetate, 1,3-butadieneand pentene nitriles, most especially preferred is ethylene.

Still further, it is possible to carbonylate mixtures of alkenescontaining internal double bonds and/or branched alkenes with saturatedhydrocarbons. Examples are raffinate 1, raffinate 2 and other mixedstreams derived from a cracker, or mixed streams derived from alkenedimerisation (butene dimerisation is one specific example) and FischerTropsch reactions.

References to vinyl esters herein include references to substituted orunsubstituted vinyl ester of formula V:R⁶⁶—C(O)OCR⁶³═CR⁶⁴R⁶⁵  Vwherein R⁶⁶ may be selected from hydrogen, alkyl, aryl, Het, halo,cyano, nitro, OR¹⁹, OC(O)R²⁰, C(O)R²¹, C(O)OR²², NR²³R²⁴, C(O)NR²⁵R²⁶,C(S)R²⁷R²⁸, SR²⁹, C(O)SR³⁰ wherein R¹⁹-R³⁰ are as defined herein.

Preferably, R⁶⁶ is selected from hydrogen, alkyl, phenyl or alkylphenyl,more preferably, hydrogen, phenyl, C₁-C₆ alkylphenyl or C₁-C₆ alkyl,such as methyl, ethyl, propyl, butyl, pentyl and hexyl, even morepreferably, C₁-C₆ alkyl, especially methyl.

Preferably, R⁶³-R⁶⁵ each independently represents hydrogen, alkyl, arylor Het as defined herein. Most preferably, R⁶³-R⁶⁵ independentlyrepresents hydrogen.

When the ethylenically unsaturated compound is a conjugated diene itcontains at least two conjugated double bonds in the molecule. Byconjugation is meant that the location of the 7c-orbital is such that itcan overlap other orbitals in the molecule. Thus, the effects ofcompounds with at least two conjugated double bonds are often differentin several ways from those of compounds with no conjugated bonds.

The conjugated diene preferably is a conjugated diene having from 4 to22, more preferably from 4 to 10 carbon atoms per molecule. Theconjugated diene can be substituted with one or more furthersubstituents selected from aryl, alkyl, hetero (preferably oxygen), Het,halo, cyano, nitro, —OR¹⁹, —OC(O)R²⁰, —C(O)R²¹, —C(O)OR²², —N(R²³)R²⁴,—C(O)N(R²⁵)R²⁶, —SR²⁹, —C(O)SR³⁰, —C(S)N(R²⁷)R²⁸ or —CF₃ wherein R¹⁹-R²⁸are as defined herein or non-substituted. Most preferably, theconjugated diene is selected from conjugated pentadienes, conjugatedhexadienes, cyclopentadiene and cyclohexadiene all of which may besubstituted as set out above or unsubstituted. Especially preferred are1,3-butadiene and 2-methyl-1,3-butadiene and most especially preferredis non-substituted 1,3-butadiene.

Bridging Group R

Preferably, the group R which is joined to A and B, as defined, onavailable adjacent atoms of the at least one aromatic ring, is alsosubstituted with one or more substituent(s) Y^(x) on one or more furtheraromatic cyclic atom(s) of the aromatic structure. Preferably, thesubstituent(s) Y^(x) on the aromatic structure has a total^(x=1−n)ΣtY^(x) of atoms other than hydrogen such that ^(X=1−n)ΣtY^(x)is ≧4, where n is the total number of substituent(s) Y^(x) and tY^(x)represents the total number of atoms other than hydrogen on a particularsubstituent Y^(x).

Typically, when there is more than one substituent Y^(x) hereinafteralso referred to as simply Y, any two may be located on the same ordifferent aromatic cyclic atoms of the aromatic structure. Preferably,there are ≦10 Y groups ie n is 1 to 10, more preferably there are 1-6 Ygroups, most preferably 1-4 Y groups on the aromatic structure and,especially, 1, 2 or 3 substituent Y groups on the aromatic structure.The substituted cyclic aromatic atoms may be carbon or hetero but arepreferably carbon.

Preferably, ^(X=1−n)ΣtY^(x) is between 4-100, more preferably, 4-60,most preferably, 4-20, especially 4-12.

Preferably, when there is one substituent Y, Y represents a group whichis at least as sterically hindering as phenyl and when there are two ormore substituents Y they are each as sterically hindering as phenyland/or combine to form a group which is more sterically hindering thanphenyl.

By sterically hindering herein, whether in the context of the groupsR⁴-R¹² described hereinafter or the substituent Y, we mean the term asreadily understood by those skilled in the art but for the avoidance ofany doubt, the term more sterically hindering than phenyl can be takento mean having a lower degree of substitution (DS) than PH₂Ph when PH₂Y(representing the group Y) is reacted with Ni(0)(CO)₄ in eightfoldexcess according to the conditions below. Similarly, references to moresterically hindering than t-butyl can be taken as references to DSvalues compared with PH₂t-Bu etc. If two Y groups are being compared andPHY¹ is not more sterically hindered than the reference then PHY¹Y²should be compared with the reference. Similarly, if three Y groups arebeing compared and PHY¹ or PHY¹Y² are not already determined to be moresterically hindered than the standard then PY¹Y²Y³ should be compared.If there are more than three Y groups they should be taken to be moresterically hindered than t-butyl.

Steric hindrance in the context of the invention herein is discussed onpage 14 et seq of “Homogenous Transition Metal Catalysis—A Gentle Art”,by C. Masters, published by Chapman and Hall 1981. Tolman (“PhosphorusLigand Exchange Equilibria on Zerovalent Nickel. A Dominant Role forSteric Effects”, Journal of American Chemical Society, 92, 1970,2956-2965) has concluded that the property of the ligands whichprimarily determines the stability of the Ni(O) complexes is their sizerather than their electronic character.

To determine the relative steric hindrance of a group Y the method ofTolman to determine DS may be used on the phosphorus analogue of thegroup to be determined as set out above.

Toluene solutions of Ni(CO)₄ were treated with an eightfold excess ofphosphorus ligand; substitution of CO by ligand was followed by means ofthe carbonyl stretching vibrations in the infrared spectrum. Thesolutions were equilibrated by heating in sealed tubes for 64 hr at100°. Further heating at 100° for an additional 74 hrs did notsignificantly change the spectra. The frequencies and intensities of thecarbonyl stretching bands in the spectra of the equilibriated solutionsare then determined. The degree of substitution can be estimatedsemi-quantitatively from the relative intensities and the assumptionthat the extinction coefficients of the bands are all of the same orderof magnitude. For example, in the case of P(C₆H₁₁)₃ the A₁ band ofNi(CO)₃L and the B₁ band of Ni(CO)₂L₂ are of about the same intensity,so that the degree of substitution is estimated at 1.5. If thisexperiment fails to distinguish the respective ligands then the diphenylphosphorus PPh₂H or di-t-butyl phosphorus should be compared to the PY₂Hequivalent as the case may be. Still further, if this also fails todistinguish the ligands then the PPh₃ or P(^(t)Bu)₃ ligand should becompared to PY₃, as the case may be. Such further experimentation may berequired with small ligands which fully substitute the Ni(CO)₄ complex.

The group Y may also be defined by reference to its cone angle which canbe defined in the context of the invention as the apex angle of acylindrical cone centred at the midpoint of the aromatic ring. Bymidpoint is meant a point in the plane of the ring which is equidistantfrom the cyclic ring atoms.

Preferably, the cone angle of the at least one group Y or the sum of thecone angles of two or more Y groups is at least 10°, more preferably, atleast 20°, most preferably, at least 30°. Cone angle should be measuredaccording to the method of Tolman (C. A. Tolman Chem. Rev. 77, (1977),313-348) except that the apex angle of the cone is now centred at themidpoint of the aromatic ring. This modified use of Tolman cone angleshas been used in other systems to measure steric effects such as thosein cyclopentadienyl zirconium ethene polymerisation catalysts (Journalof Molecular Catalysis: Chemical 188, (2002), 105-113).

The substituents Y are selected to be of the appropriate size to providesteric hindrance with respect to the active site between the Q¹ and Q²atoms. However, it is not known whether the substituent is preventingthe metal leaving, directing its incoming pathway, generally providing amore stable catalytic confirmation, or acting otherwise.

A particularly preferred ligand is found when Y represents —SR⁴⁰R⁴¹R⁴²wherein S represents Si, C, N, S, O or aryl and R⁴⁰R⁴¹R⁴² are as definedhereinafter. Preferably each Y and/or combination of two or more Ygroups is at least as sterically hindering as t-butyl.

More preferably, when there is only one substituent Y, it is at least assterically hindering as t-butyl whereas where there are two or moresubstituents Y, they are each at least as sterically hindering as phenyland at least as sterically hindering as t-butyl if considered as asingle group.

Preferably, when S is aryl, R⁴⁰, R⁴¹ and R⁴² are independently hydrogen,alkyl, —BQ³-X³(X⁴) (wherein B, X³ and X⁴ are as defined herein and Q³ isdefined as Q¹ or Q² above), phosphorus, aryl, arylene, alkaryl,arylenalkyl, alkenyl, alkynyl, het, hetero, halo, cyano, nitro, —OR¹⁹,—OC(O)R²⁰, —C(O)R²¹, —C(O)OR²², —N(R²³) R²⁴, —C(O)N(R²⁵)R²⁶, —SR²⁹,—C(O)SR³⁰, —C(S)N(R²⁷)R²⁸, —CF₃, —SiR⁷¹R⁷²R⁷³ or alkylphosphorus.

R¹⁹-R³⁰ referred to herein may independently be generally selected fromhydrogen, unsubstituted or substituted aryl or unsubstituted orsubstituted alkyl, in addition R²¹ may be nitro, halo, amino or thio.

Preferably, when S is Si, C, N, S or O, R⁴⁰, R⁴¹ and R⁴² areindependently hydrogen, alkyl, phosphorus, aryl, arylene, alkaryl,aralkyl, arylenalkyl, alkenyl, alkynyl, het, hetero, halo, cyano, nitro,—OR¹⁹, —OC(O)R²⁰, —C(O)R²¹, —C(O)OR²², —N(R²³)R²⁴, —C(O)N(R²⁵)R²⁶,—SR²⁹, —C(O)SR³⁰, —C(S)N(R²⁷)R²⁸, —CF₃, —SiR⁷¹R⁷²R⁷³, or alkylphosphoruswherein at least one of R⁴⁰-R⁴² is not hydrogen and wherein R¹⁹-R³⁰ areas defined herein, and R⁷¹-R⁷³ are defined as R⁴⁰-R⁴² but are preferablyC₁-C₄ alkyl or phenyl.

Preferably, S is Si, C or aryl. However, N, S or O may also be preferredas one or more of the Y groups in combined or in the case of multiple Ygroups. For the avoidance of doubt, as oxygen or sulphur can bebivalent, R⁴⁰-R⁴² can also be lone pairs.

Preferably, alternatively or in addition to group Y, the aromaticstructure may be unsubstituted or, when possible be further substitutedwith groups selected from Y (on the non-aromatic cyclic atoms), alkyl,aryl, arylene, alkaryl, aralkyl, arylenalkyl, alkenyl, alkynyl, het,hetero, halo, cyano, nitro, —OR¹⁹, —OC(O)R²⁰, —C(O)R²¹, —C(O)OR²²,—N(R²³)R²⁴, —C(O)N(R²⁵)R²⁶, —SR²⁹, —C(O)SR³⁰, —C(S)N(R²⁷)R²⁸, —CF₃,—SiR⁷¹R⁷²R⁷³, or alkylphosphorus wherein R¹⁹-R³⁰ are as defined hereinand in the case of Y or a group fulfilling the definition of Y of thefirst aspect the attachment is to a non-cyclic aromatic atom of thearomatic structure; and R⁷¹-R⁷³ are defined as R⁴⁰-R⁴² but arepreferably C₁-C₄ alkyl or phenyl. In addition, the at least one aromaticring can be part of a metallocene complex, for instance when R is acyclopentadienyl or indenyl anion it may form part of a metal complexsuch as ferrocenyl, ruthenocyl, molybdenocenyl or indenyl equivalents.

Such complexes should be considered as aromatic structures within thecontext of the present invention so that, when they include more thanone aromatic ring, the substituent(s) Y^(x) may be on the same aromaticring as that to which the Q¹ and Q² atoms are linked or a furtheraromatic ring of the structure. For instance, in the case of ametallocene, the substituent Y^(x) may be on any one or more rings ofthe metallocene structure and this may be the same or a different ringto which Q¹ and Q² are linked.

Suitable metallocene type ligands which may be substituted with a groupY as defined herein will be known to the skilled person and areextensively defined in WO 04/024322. A particularly preferred Ysubstituent for such aromatic anions is when S is Si.

In general, however, when S is aryl, the aryl may be furtherunsubstituted or substituted with, in addition to R⁴⁰, R⁴¹, R⁴², any ofthe further substituents defined for the aromatic structure above.

More preferred Y substituents in the present invention may be selectedfrom t-alkyl or t-alkyl,aryl such as -t-butyl or 2-phenylprop-2-yl,—SiMe₃, -phenyl, alkylphenyl-, phenylalkyl- or phosphinoalkyl—such asphosphinomethyl.

Preferably, when S is Si or C and one or more of R⁴⁰-R⁴² are hydrogen,at least one of R⁴⁰-R⁴² should be sufficiently bulky to give therequired steric hindrance and such groups are preferably phosphorus,phosphinoalkyl-, a tertiary carbon bearing group such as -t-butyl,-aryl, -alkaryl, -aralkyl or tertiary silyl.

Preferably, whether Y is present or not, the hydrocarbyl aromaticstructure has, including substituents, from 5 up to 70 cyclic atoms,more preferably, 5 to 40 cyclic atoms, most preferably, 5-22 cyclicatoms, especially 5 or 6 cyclic atoms, if not a metallocene complex.

Preferably, the hydrocarbyl aromatic structure may be monocyclic orpolycyclic. The cyclic aromatic atoms may be carbon or hetero, whereinreferences to hetero herein are references to sulphur, oxygen and/ornitrogen. However, it is preferred that the Q¹ and Q² atoms are linkedto available adjacent cyclic carbon atoms of the at least one aromaticring. Typically, when the cyclic hydrocarbyl structure is polycylic itis preferably bicyclic or tricyclic. The further cycles in the aromaticstructure may or may not themselves be aromatic and aromatic structureshould be understood accordingly. A non-aromatic cyclic ring(s) asdefined herein may include unsaturated bonds. By cyclic atom is meant anatom which forms part of a cyclic skeleton.

Preferably, the bridging group —R, whether further substituted orotherwise preferably comprises less than 200 atoms, more preferably,less than 150 atoms, more preferably, less than 100 atoms.

By the term one further aromatic cyclic atom of the aromatic structureis meant any further aromatic cyclic atom in the aromatic structurewhich is not an available adjacent cyclic atom of the at least onearomatic ring to which the Q¹ or Q² atoms are linked, via the linkinggroup.

Preferably, the immediately adjacent cyclic atoms on either side of thesaid available adjacent cyclic atoms are preferably not substituted. Asan example, an aromatic phenyl ring joined to a Q¹ atom via position 1on the ring and joined to a Q² atom via position 2 on the ring haspreferably one or more said further aromatic cyclic atoms substituted atring position 4 and/or 5 and the two immediately adjacent cyclic atomsto the said available adjacent cyclic atoms not substituted at positions3 and 6. However, this is only a preferred substituent arrangement andsubstitution at ring positions 3 and 6, for example, is possible.

The term aromatic ring means that the at least one ring to which the Q¹and Q² atom are linked via B & A respectively is aromatic, and aromaticshould preferably be interpreted broadly to include not only a phenyl,cyclopentadienyl anion, pyrollyl, pyridinyl, type structures but otherrings with aromaticity such as that found in any ring with delocalisedPi electrons able to move freely in the said ring.

Preferred aromatic rings have 5 or 6 atoms in the ring but rings with4n+2 pi electrons are also possible such as [14] annulene, [18]annulene, etc

The hydrocarbyl aromatic structure R may be selected from benzene-1,2diyl, ferrocene-1,2-diyl, naphthalene-2,3-diyl, 4 or 5 methylbenzene-1,2-diyl, 1′-methyl ferrocene-1,2-diyl, 4 and/or 5t-alkylbenzene-1,2-diyl, 4,5-diphenyl-benzene-1,2-diyl, 4 and/or5-phenyl-benzene-1,2-diyl, 4,5-di-t-butyl-benzene-1,2-diyl, 4 or5-t-butylbenzene-1,2-diyl, 2, 3, 4 and/or 5t-alkyl-naphthalene-8,9-diyl, 1H-inden-5,6-diyl, 1, 2 and/or 3methyl-1H-inden-5,6-diyl, 4,7 methano-1H-indene-1,2-diyl, 1, 2 and/or3-dimethyl-1H-inden 5,6-diyls,1,3-bis(trimethylsilyl)-isobenzofuran-5,6-diyl,4-(trimethylsilyl)benzene-1,2 diyl, 4-phosphinomethyl benzene-1,2 diyl,4-(2′-phenylprop-2′-yl)benzene 1,2 diyl, 4-dimethylsilylbenzene-1,2diyl,4-di-t-butyl, methylsilyl benzene-1,2diyl,4-(t-butyldimethylsilyl)-benzene-1,2diyl,4-t-butylsilyl-benzene-1,2diyl, 4-(tri-t-butylsilyl)-benzene-1,2diyl,4-(2′-tert-butylprop-2′-yl)benzene-1,2 diyl, 4-(2′,2′,3′,4′,4′pentamethyl-pent-3′-yl)-benzene-1,2diyl, 4-(2′,2′,4′,4′-tetramethyl,3′-t-butyl-pent-3′-yl)-benzene-1,2 diyl, 4-(or1′)_(t)-alkylferrocene-1,2-diyl, 4′,5-diphenyl-ferrocene-1,2-diyl,1′)phenyl-ferrocene-1,2-diyl, 4,5-di-t-butyl-ferrocene-1,2-diyl, 4-(or1′)_(t)-butylferrocene-1,2-diyl, 4-(or 1′) (trimethylsilyl)ferrocene-1,2diyl, 4-(or 1′)phosphinomethyl ferrocene-1,2 diyl, 4-(or1′)(2′-phenylprop-2′-yl)ferrocene-1,2 diyl, 4-(or1′)dimethylsilylferrocene-1,2diyl, 4-(or 1′)di-t-butyl, methylsilylferrocene-1,2diyl, 4-(or 1′)(t-butyldimethylsilyl)-ferrocene-1,2diyl,4-(or 1′)_(t)-butylsilyl-ferrocene-1,2diyl, 4-(or1′)(tri-t-butylsilyl)-ferrocene-1,2diyl, 4-(or1′)(2′-tert-butylprop-2′-yl)ferrocene-1,2 diyl, 4-(or 1′)(2′,2′,3′,4′,4′pentamethyl-pent-3′-yl)-ferrocene-1,2diyl, 4-(or1′)(2′,2′,4′,4′-tetramethyl, 3′-t-butyl-pent-3′-yl)-ferrocene-1,2 diyl.

In the structures herein, where there is more than one stereisomericform possible, all such stereoisomers are intended.

As mentioned above, in some embodiments, there may be two or more ofsaid Y and/or non-Y substituents on further aromatic cyclic atoms of thearomatic structure. Optionally, the said two or more substituents may,especially when themselves on neighbouring cyclic aromatic atoms,combine to form a further ring structure such as a cycloaliphatic ringstructure.

Such cycloaliphatic ring structures may be saturated or unsaturated,bridged or unbridged, substituted with alkyl, Y groups as definedherein, aryl, arylene, alkaryl, aralkyl, arylenalkyl, alkenyl, alkynyl,het, hetero, halo, cyano, nitro, —OR¹⁹, —OC(O)R²⁰, —C(O)R²¹, —C(O)OR²²,—N(R²³)R²⁴, C(O)N(R²⁵)R²⁶, —SR²⁹, —C(O)SR³⁰, —C(S)N(R²⁷)R²⁸, —CF₃,—SiR⁷¹R⁷²R⁷³, or phosphinoalkyl wherein, when present, at least one ofR⁴⁰-R⁴² is not hydrogen and wherein R¹⁹-R²⁰ are as defined herein; andR⁷¹-R⁷³ are defined as R⁴⁰-R⁴² but are preferably C₁-C₄ alkyl or phenyland/or be interrupted by one or more (preferably less than a total of 4)oxygen, nitrogen, sulphur, silicon atoms or by silano or dialkyl silicongroups or mixtures thereof.

Examples of such structures include piperidine, pyridine, morpholine,cyclohexane, cycloheptane, cyclooctane, cyclononane, furan, dioxane,alkyl substituted DIOP, 2-alkyl substituted 1,3 dioxane, cyclopentanone,cyclohexanone, cyclopentene, cyclohexene, cyclohexadiene, 1,4 dithiane,piperizine, pyrollidine, thiomorpholine, cyclohexenone,bicyclo[4.2.0]octane, bicyclo[4.3.0]nonane, adamantane, tetrahydropyran,dihydropyran, tetrahydrothiopyran, tetrahydro-furan-2-one, deltavalerolactone, gamma-butyrolactone, glutaric anhydride,dihydroimidazole, triazacyclononane, triazacyclodecane, thiazolidine,hexahydro-1H-indene (5,6 diyl), octahydro-4,7 methano-indene (1,2 diyl)and tetrahydro-1H-indene (5,6 diyl) all of which may be unsubstituted orsubstituted as defined for aryl herein.

However, whether forming combined groups or otherwise, it is preferredthat the immediate adjacent aromatic cyclic atoms, on either side of thesaid available adjacent cyclic atoms to which Q¹ and Q² are linked, viathe said linking group, are un-substituted and preferable substitutionis elsewhere on the at least one aromatic ring or elsewhere in thearomatic structure when the aromatic structure comprises more than onearomatic ring and the preferred position of combined Y substituentsshould be understood accordingly.

Specific but non-limiting examples of unsubstituted and substitutedaromatic bridged bidentate ligands within this invention are set out inthe claims.

In the said lists of ligands the term “phosphinomethyl-adamantyl” meansany one of the following groups2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl,2-phosphinomethyl-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl2-phosphinomethyl-1,3,5,7-tetra(trifluoromethyl)-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl,2-phosphinomethyl-perfluoro-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo{3.3.1.1[3.7]}-decylor2-phosphinomethyl-1,3,5-tri(trifluoromethyl)-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl.

In the said lists of ligands the term “phospha-adamantyl” means any oneof the following groups2-phospha-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl,2-phospha-1,3,5-trimethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl,2-phospha-1,3,5,7-tetra(trifluoromethyl)-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl,perfluoro(2-phospha-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo{3.3.1.1[3.7]}-decylor2-phospha-1,3,5-tri(trifluoromethyl)-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyl.

For avoidance of doubt the structure of2-phosphinomethyl-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decyletc is as follows: —

Similarly, the structure of2-phospha-1,3,5,7-tetramethyl-6,9,10-trioxatricyclo-{3.3.1.1[3.7]}decylis as follows: —

It will be appreciated that in all cases the phosphorus is attached totwo tertiary carbon atoms in the phospha-adamantyl skeleton.

Selected structures of ligands of the invention include: —

-   1-(di-tert-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)benzene

-   1-(di-tert-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)ferrocene,

-   1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)-4,5-diphenyl    benzene;

wherein Py-2-yl represents pyridine-2-yl

-   1-(P,P adamantyl, t-butyl    phosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)-4,5-diphenylbenzene;

-   1-(di-pyridin-2-ylphosphinomethyl)-2-(di-tert-butylphosphino)-4-(trimethylsilyl)benzene

-   1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)-4,5-diphenyl    ferrocene;

In the above example structures of ligands one or more of the X³-X⁴tertiary carbon bearing groups, t-butyl, attached to the Q¹ and/or Q²group phosphorus may be replaced by a suitable alternative. Preferredalternatives are adamantyl, 1,3 dimethyl adamantyl, congressyl,norbornyl or 1-norbondienyl, or X³ and X⁴ together form together withthe phosphorus a 2-phospha-tricyclo[3.3.1.1{3,7}decyl group such as2-phospha-1,3,5,7-tetramethyl-6,9,10-trioxadamantyl or2-phospha-1,3,5-trimethyl-6,9,10-trioxadamantyl. In most embodiments, itis preferred that the univalent X¹/X² groups and X³/X⁴ groups are thesame but it may also be advantageous to use different groups to producefurther asymmetry around the active site in these selected ligands andgenerally in this invention.

Similarly, one of the linking groups A or B may be absent so that only Aor B is methylene and the phosphorus atom not connected to the methylenegroup is connected directly to the ring carbon giving a 3 carbon bridgebetween the phosphorus atoms.

Substituents X²⁻⁴

Subject to the restrictions defined in the claims and the preferredsituation where X² is the same as X¹, the substituents X²⁻⁴,particularly X³ and X⁴ may represent various groups. For instance, thegroup X² may represent CH(R⁴)(R⁵), X³ may represent CR⁷(R⁸)(R⁹) and X⁴may represent CR¹⁰(R¹¹)(R¹²), wherein R⁴ to R⁵ represent hydrogen,alkyl, aryl or het and R⁷-R¹² represent alkyl, aryl or het.Alternatively, X² represents Ar. Preferably, when X² represents Ar, thegroup is substituted by a C₁-C₇ alkyl group, O—C₁-C₇ alkyl group, —CN,—F, —Si(alkyl)₃, —COOalkyl, —C(O)—, or —CF₃. Preferably, the Ar group issubstituted at the carbon adjacent the Q bonded ring carbon i.e. theortho position in a phenyl ring.

Particularly preferred is when the organic groups R⁷-R⁹ and/or R¹⁰-R¹²or, alternatively, R⁷-R¹² when associated with their respective tertiarycarbon atom(s) form composite groups which are at least as stericallyhindering as t-butyl(s).

The steric groups may be cyclic, part-cyclic or acyclic. When cyclic orpart cyclic, the group may be substituted or unsubstituted or saturatedor unsaturated. The cyclic or part cyclic groups may preferably contain,including the tertiary carbon atom(s), from C₄-C₃₄, more preferablyC₈-C₂₄, most preferably C₁₀-C₂₀ carbon atoms in the cyclic structure.The cyclic structure may be substituted by one or more substituentsselected from halo, cyano, nitro, OR¹⁹, OC(O)R²⁰, C(O)R²¹, C(O)OR²²,NR²³R²⁴, C(O)NR²⁵R²⁶, SR²⁹, C(O)SR³⁰, C(S)NR²⁷R²⁸, aryl or Het, whereinR¹⁹ to R³⁰ each independently represent hydrogen, aryl or alkyl, and/orbe interrupted by one or more oxygen or sulphur atoms, or by silano ordialkylsilicon groups.

In particular, when cyclic, X³ and/or X⁴ may represent congressyl,norbornyl, 1-norbornadienyl or adamantyl.

X³ and X⁴ together with Q¹ to which they are attached may form anoptionally substituted 2-Q1-tricyclo[3.3.1.1{3,7}]decyl group orderivative thereof, or X³ and X⁴ together with Q¹ to which they areattached may form a ring system of formula 1b

Alternatively, one or more of the groups X³ and/or X⁴ may represent asolid phase to which the ligand is attached.

Particularly preferred is when X³ and X⁴ are the same and X¹ and X² arethe same.

In preferred embodiments, R⁴ to R⁵ each independently representhydrogen, alkyl, aryl, or Het and R⁷ to R¹² each independently representalkyl, aryl, or Het;

R¹⁹ to R³⁰ each independently represent hydrogen, alkyl, aryl or Het;

R⁴⁹ and R⁵⁴, when present, each independently represent hydrogen, alkylor aryl;

R⁵⁰ to R⁵³, when present, each independently represent alkyl, aryl orHet;

YY², when present, independently represents oxygen, sulfur or N—R⁵⁵,wherein R⁵⁵ represents hydrogen, alkyl or aryl.

Preferably, R⁴ to R⁵ and R⁷ to R¹² when not hydrogen each independentlyrepresent alkyl or aryl. More preferably, R⁴ to R⁵ and R⁷ to R¹² eachindependently represent C₁ to C₆ alkyl, C₁-C₆ alkyl phenyl (wherein thephenyl group is optionally substituted as aryl as defined herein) orphenyl (wherein the phenyl group is optionally substituted as aryl asdefined herein). Even more preferably, R⁴ to R⁵ and R⁷ to R¹² eachindependently represent C₁ to C₆ alkyl, which is optionally substitutedas alkyl as defined herein. Most preferably, R⁴ to R⁵ and R⁷ to R¹² eachrepresent non-substituted C₁ to C₈ alkyl such as methyl, ethyl,n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, pentyl, hexyl andcyclohexyl, especially methyl.

In a particularly preferred embodiment of the present invention R⁷ andR¹⁰ each represent the same alkyl, aryl or Het moiety as defined herein,R⁸ and R¹¹ each represent the same alkyl, aryl or Het moiety as definedherein, and R⁹ and R¹² each represent the same alkyl, aryl or Het moietyas defined herein. More preferably R⁷ and R¹⁰ each represent the sameC₁-C₆ alkyl, particularly non-substituted C₁-C₆ alkyl, such as methyl,ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, pentyl,hexyl or cyclohexyl; R⁸ and R¹¹ each independently represent the sameC₁-C₆ alkyl as defined above; and R⁹ and R¹² each independentlyrepresent the same C₁-C₆ alkyl as defined above. For example: R⁷ and R¹⁶each represent methyl; R⁸ and R¹¹ each represent ethyl; and R⁹ and R¹²each represent n-butyl or n-pentyl.

In an especially preferred embodiment of the present invention each R⁷to R¹² group represents the same alkyl, aryl, or Het moiety as definedherein. Preferably, when alkyl groups, each R⁷ to R¹² represents thesame C₁ to C₆ alkyl group, particularly non-substituted C₁-C₆ alkyl,such as methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl,tert-butyl, pentyl, hexyl and cyclohexyl. More preferably, each R⁷ toR¹² represents methyl or tert-butyl, most preferably, methyl.

The adamantyl, congressyl, norbornyl or 1-norborndienyl group mayoptionally comprise, besides hydrogen atoms, one or more substituentsselected from alkyl, —OR¹⁹, —OC(O)R²⁰, halo, nitro, —C(O)R²¹, —C(O)OR²²,cyano, aryl, —N(R²³)R²⁴, —C(O)N(R²⁵)R²⁶, —C(S)N(R²⁷)R²⁸, —SR²⁹,—C(O)SR³⁰, —CF₃, —P(R⁵⁶) R⁵⁷, —PO(R⁵⁸)(R⁵⁹), —PO₃H₂, —PO(OR⁶⁰)(OR⁶¹), or—SO₃R⁶², wherein R¹⁹-R³⁰, alkyl, halo, cyano and aryl are as definedherein and R⁵⁶ to R⁶² each independently represent hydrogen, alkyl, arylor Het.

Suitably, when the adamantyl, congressyl, norbornyl or 1-norborndienylgroup is substituted with one or more substituents as defined above,highly preferred substituents include unsubstituted C₁ to C₈ alkyl,—OR¹⁹, —OC(O)R²⁰, phenyl, —C(O)OR²², fluoro, —SO₃H, —N(R²³)R²⁴,—P(R⁵⁶)R⁵⁷, —C(O)N(R²⁵)R²⁶ and —PO(R⁵⁸)(R⁵⁹), —CF₃, wherein R¹⁹represents hydrogen, unsubstituted C₁-C₈ alkyl or phenyl, R²⁰, R²², R²³,R²⁴, R²⁵, R²⁶ each independently represent hydrogen or unsubstitutedC₁-C₈ alkyl, R⁵⁶ to R⁵⁹ each independently represent unsubstituted C₁-C₈alkyl or phenyl. In a particularly preferred embodiment the substituentsare C₁ to C₈ alkyl, more preferably, methyl such as found in 1,3dimethyl adamantyl.

Suitably, the adamantyl, congressyl, norbornyl or 1-norborndienyl groupmay comprise, besides hydrogen atoms, up to 10, substituents as definedabove, preferably up to 5 substituents as defined above, more preferablyup to 3 substituents as defined above. Suitably, when the adamantyl,congressyl, norbornyl or 1-norborndienyl group comprises, besideshydrogen atoms, one or more substituents as defined herein, preferablyeach substituent is identical. Preferred substituents are unsubstitutedC₁-C₈ alkyl and trifluoromethyl, particularly unsubstituted C₁-C₈ alkylsuch as methyl. A highly preferred adamantyl, congressyl, norbornyl or1-norborndienyl group comprises hydrogen atoms only i.e. the adamantylcongressyl, norbornyl or 1-norborndienyl group is not substituted.

Preferably, when more than one adamantyl, congressyl, norbornyl or1-norborndienyl group is present in a compound of formula I, each suchgroup is identical.

The 2-Q¹-tricyclo[3.3.1.1.{3,7}]decyl group (referred to hereinafter asa 2-meta-adamantyl group for convenience wherein 2-meta-adamantyl is areference to Q¹ being an arsenic, antimony or phosphorus atom i.e.2-arsa-adamantyl and/or 2-stiba-adamantyl and/or 2-phospha-adamantyl,preferably, 2-phospha-adamantyl) may optionally comprise, besidehydrogen atoms, one or more substituents. Suitable substituents includethose substituents as defined herein in respect of the adamantyl group.Highly preferred substituents include alkyl, particularly unsubstitutedC₁-C₈ alkyl, especially methyl, trifluoromethyl, —OR¹⁹ wherein R¹⁹ is asdefined herein particularly unsubstituted C₁-C₈ alkyl or aryl, and4-dodecylphenyl. When the 2-meta-adamantyl group includes more than onesubstituent, preferably each substituent is identical.

Preferably, the 2-meta-adamantyl group is substituted on one or more ofthe 1, 3, 5 or 7 positions with a substituent as defined herein. Morepreferably, the 2-meta-adamantyl group is substituted on each of the 1,3 and 5 positions. Suitably, such an arrangement means the Q¹ atom ofthe 2-meta-adamantyl group is bonded to carbon atoms in the adamantylskeleton having no hydrogen atoms. Most preferably, the 2-meta-adamantylgroup is substituted on each of the 1, 3, 5 and 7 positions. When the2-meta-adamantyl group includes more than 1 substituent preferably eachsubstituent is identical. Especially preferred substituents areunsubstituted C₁-C₈ alkyl and haloalkyls, particularly unsubstitutedC₁-C₈ alkyl such as methyl and fluorinated C₁-C₈ alkyl such astrifluoromethyl.

Preferably, 2-meta-adamantyl represents unsubstituted 2-meta-adamantylor 2-meta-adamantyl substituted with one or more unsubstituted C₁-C₈alkyl substituents, or a combination thereof.

Preferably, the 2-meta-adamantyl group includes additional heteroatoms,other than the 2-Q atom, in the 2-meta-adamantyl skeleton. Suitableadditional heteroatoms include oxygen and sulphur atoms, especiallyoxygen atoms. More preferably, the 2-meta-adamantyl group includes oneor more additional heteroatoms in the 6, 9 and 10 positions. Even morepreferably, the 2-meta-adamantyl group includes an additional heteroatomin each of the 6, 9 and 10 positions. Most preferably, when the2-meta-adamantyl group includes two or more additional heteroatoms inthe 2-meta-adamantyl skeleton, each of the additional heteroatoms areidentical. Preferably, the 2-meta-adamantyl includes one or more oxygenatoms in the 2-meta-adamantyl skeleton. An especially preferred2-meta-adamantyl group, which may optionally be substituted with one ormore substituents as defined herein, includes an oxygen atom in each ofthe 6, 9 and 10 positions of the 2-meta-adamantyl skeleton.

Highly preferred 2-meta-adamantyl groups as defined herein include2-phospha-1,3,5,7-tetramethyl-6,9,10-trioxadamantyl,2-phospha-1,3,5-trimethyl-6,9,10-trioxadamantyl,2-phospha-1,3,5,7-tetra(trifluoromethyl)-6,9,10-trioxadamantyl group,and 2-phospha-1,3,5-tri(trifluoromethyl)-6,9,10-trioxadamantyl group.Most preferably, the 2-phospha-adamantyl is selected from2-phospha-1,3,5,7-tetramethyl-6,9,10-trioxadamantyl group or2-phospha-1,3,5, -trimethyl-6,9,10-trioxadamantyl group.

The 2-meta-adamantyl group may be prepared by methods well known tothose skilled in the art. Suitably, certain 2-phospha-adamantylcompounds are obtainable from Cytec Canada Inc, Canada. Likewisecorresponding 2-meta-adamantyl compounds of formula I etc may beobtained from the same supplier or prepared by analogous methods.

Subject to the restrictions of the claims, preferred embodiments of thepresent invention include those wherein:

X³ represents CR⁷(R⁹)(R⁹), X⁴ represents CR¹⁹(R¹¹) (R¹²), X¹ representsC(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰² and X² represents C(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰²;

X³ represents CR⁷(R⁸)(R⁹), X⁴ represents CR¹⁰(R¹¹)(R¹²), and X¹ and X²represent

X³ represents CR⁷(R⁸)(R⁹), X⁴ represents adamantyl, and X¹ and X²represent

X³ represents CR⁷(R⁸)(R⁹), X⁴ represents adamantyl and X¹ representsC(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰² and X² represents C(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰²;X³ represents CR⁷(R⁸)(R⁹), X⁴ represents congressyl, and X¹ representsC(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰² and X² represents C(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰²;X³ represents CR⁷(R⁸)(R⁹), X⁴ represents congressyl, and X¹ and X²represent

X³ and X⁴ independently represent adamantyl, and X¹ and X² represent

X³ and X⁴ independently represent adamantyl, and X¹ representsC(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰² and X² represents C(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰²;X³ and X⁴ together with Q¹ to which they are attached may form a ringsystem of formula 1b

and X¹ represents C(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰² and X² representsC(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰²;X³ and X⁴ independently represent congressyl, and X¹ and X² represent

X³ and X⁴ together with Q¹ to which they are attached may form a ringsystem of formula 1b

and X¹ and X² represent

X³ and X⁴ independently represent congressyl, and X¹ representsC(R¹⁰¹R¹⁰²) NR¹⁰¹R¹⁰² and X² represents C(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰²;X³ and X⁴ together with Q¹ to which they are attached form a2-phospha-adamantyl group, and X¹ represents C(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰² and X²represents C(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰²;X³ and X⁴ together with Q¹ to which they are attached form a2-phospha-adamantyl group, and X¹ and X² represent

Highly preferred embodiments of the present invention include thosewherein:

X³ represents CH⁷(R⁸)(R⁹), X⁴ represents CR¹⁰ (R¹¹)(R¹²), X¹ representsC(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰² and X² represents C(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰²; especiallywhere R⁷-R¹² are methyl and R¹⁰¹ and R¹⁰² are either hydrogen, methyl orethyl; and

X³ represents CR⁷(R⁸)(R⁹), X⁴ represents CR¹⁰(R¹¹)(R¹²), and X¹ and X²represent

Preferably in a compound of formula I, X³ is identical to X⁴ and/or X¹is identical to X².

Particularly preferred combinations in the present invention includethose wherein: —

-   (1) represents CR⁷(R⁸)(R⁹), X⁴ represents CR¹⁰(R¹¹)(R¹²) and X¹ and    X² represent

-   -   A and B are the same and represent —CH₂—;    -   Q¹ and Q² both represent phosphorus linked to the R group at        ring positions 1 and 2.

-   (2) X³ represents CR⁷(R⁸)(R⁹), X⁴ represents CR¹⁰(R¹¹)(R¹²), X¹    represents C(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰² and X² represents    C(R¹⁰¹R¹⁰²)NR¹⁰¹R¹⁰²;    -   A and B are the same and represent —CH₂—;    -   Q¹ and Q² both represent phosphorus linked to the R group at        ring positions 1 and 2.

-   (3) X³ and X⁴ together with Q¹ to which they are attached form a    2-phospha-adamantyl group, and X¹ and X² represent

-   -   A and B are the same and represent —CH₂—;    -   Q¹ and Q² both represent phosphorus linked to the R group at        ring positions 1 and 2.

-   (4) X³ and X⁴ represent adamantyl and X¹ and X² represent

-   -   A and B are the same and represent —CH₂—;    -   Q¹ and Q² both represent phosphorus linked to the R group at        ring positions 1 and 2.

-   Preferably, in the above embodiments, R¹⁰¹ and R¹⁰² are hydrogen,    methyl or ethyl.

Preferably, in the compound of formula I, A and B each independentlyrepresents C₁ to C₆ alkylene which is optionally substituted as definedherein, for example with alkyl groups. Preferably, the lower alkylenegroups which A and B represent are non-substituted. Particularlypreferred alkylenes which A and B may independently represent are —CH₂—or —C₂H₄—. Most preferably, each of A and B represent the same alkyleneas defined herein, particularly —CH₂—. Alternatively, one of A or B isomitted ie Q² or Q¹ is connected directly to the group R and the other Qgroup is not connected directly to the group R and is a C₁ to C₆alkylene, preferably —CH₂— or —C₂H₄—, most preferably, —CH₂—.

Still further preferred compounds of formula I include those wherein:

R⁷ to R¹² are alkyl and are the same and preferably, each represents C₁to C₆ alkyl, particularly methyl.

Especially preferred specific compounds of formula I include thosewherein:

each R⁷ to R¹² is the same and represents methyl;

A and B are the same and represent —CH₂—;

R represents benzene-1,2-diyl.

The invention not only extends to novel bidentate ligands of formula (I)but also novel complexes of such ligands with the metal of Group 8, 9 or10 or a compound thereof.

DEFINITIONS

The term “lower alkylene” which A and B represent in a compound offormula I, when used herein, includes C₀-C₁₀ or C₁ to C₁₀ groups,preferably, C₀, C₁ or C₂, more preferably, C₁, most preferably,methylene which, in the case of C₁ to C₁₀, can be bonded at two placeson the group to thereby connect the group Q¹ or Q² to the R group, and,in the latter case, is otherwise defined in the same way as “alkyl”below. Nevertheless, in the latter case, methylene is most preferred. Inthe former case, by C₀ is meant that the group Q¹ or Q² is connecteddirectly to the R group and there is no C₁-C₁₀ lower alkylene group andin this case only one of A and B is a C₁-C₁₀ lower alkylene. In anycase, when one of the groups A or B is C₀ then the other group cannot beC₀ and must be a C₁-C₁₀ group as defined herein and, therefore, at leastone of A and B is a C₁-C₁₀ “lower alkylene” group.

The term “alkyl” when used herein, means C₁ to C₁₀ alkyl, preferably, C₁to C₆ alkyl, more preferably, C₁ to C₄ alkyl and includes methyl, ethyl,ethenyl, propyl, propenyl butyl, butenyl, pentyl, pentenyl, hexyl,hexenyl and heptyl groups. Unless otherwise specified, alkyl groups may,when there is a sufficient number of carbon atoms, be linear or branched(particularly preferred branched groups include t-butyl and isopropyl),be saturated or unsaturated, be cyclic, acyclic or part cyclic/acyclic,be unsubstituted, substituted or terminated by one or more substituentsselected from halo, cyano, nitro, OR¹⁹, OC(O)R²⁰, C(O)R²¹, C(O)OR²²,NR²³R²⁴, C(O)NR²⁵R²⁶, SR²⁹, C(O)SR³⁰, C(S)NR²⁷R²⁸, unsubstituted orsubstituted aryl, or unsubstituted or substituted Het and/or beinterrupted by one or more (preferably less than 4) oxygen, sulphur,silicon atoms, or by silano or dialkylsilicon groups, or mixturesthereof.

The term “fluoroalkyl” is defined in the same way as alkyl except anyone or more of the hydrogen groups may be replaced by a fluoride.

R⁴, R⁵, R⁷ to R¹² and R¹³-R¹⁸ each independently represent alkyl, aryl,or Het unless X² is joined to the Q² atom via a non tertiary carbon inwhich case they can each also represent hydrogen.

R¹⁹ to R³⁰ herein each independently represent hydrogen, halo,unsubstituted or substituted aryl or unsubstituted or substituted alkyl,or, in the case of R²¹, additionally, halo, nitro, cyano, thio andamino. Preferably, R¹⁹ to R³⁰ represents hydrogen, unsubstituted C₁-C₈alkyl or phenyl, more preferably, hydrogen or unsubstituted C₁-C₈ alkyl.

R⁴⁹ and R⁵⁴ each independently represent hydrogen, alkyl or aryl. R⁵⁰ toR⁵³ each independently represent alkyl, aryl or Het. YY¹ and YY² eachindependently represent oxygen, sulfur or N—R⁵⁵, wherein R⁵⁵ representshydrogen, alkyl or aryl.

R¹⁰¹ and R¹⁰² represent optional substituents hydrogen, aryl, alkyl orfluoroalkyl

The term “Ar” or “aryl” when used herein, includes five-to-ten-membered,preferably five to eight membered, carbocyclic aromatic or pseudoaromatic groups, such as phenyl, cyclopentadienyl and indenyl anions andnaphthyl, which groups may be unsubstituted or as one option substitutedwith one or more substituents selected from unsubstituted or substitutedaryl, alkyl (which group may itself be unsubstituted or substituted orterminated as defined herein), Het (which group may itself beunsubstituted or substituted or terminated as defined herein), halo,cyano, nitro, OR¹⁹, OC(O)R²⁰, C(O)R²¹, C(O)OR²², NR²³R²⁴, C(O)NR²⁵R²⁶,SR²⁹, C(O)SR³⁰ or C(S)NR²⁷R²⁸ wherein R¹⁹ to R³⁰ are as defined herein.

The term “alkenyl” when used herein, means C₂ to alkenyl, preferably, C₁to C₆ alkenyl, more preferably, C₁ to C₄ alkenyl and includes ethenyl,propenyl, butenyl, pentenyl, and hexenyl groups. Unless otherwisespecified, alkenyl groups may, when there is a sufficient number ofcarbon atoms, be linear or branched, be saturated or unsaturated, becyclic, acyclic or part cyclic/acyclic, be unsubstituted, substituted orterminated by one or more substituents selected from halo, cyano, nitro,OR¹⁹, OC(O)R²⁰, C(O)R²¹, C(O)OR²², NR²³R²⁴, C(O)NR²⁵R²⁶, SR²⁹, C(O)SR³⁰,C(S)NR²⁷R²⁸, unsubstituted or substituted aryl, or unsubstituted orsubstituted Het, wherein R¹⁹ to R³⁰ are defined herein and/or beinterrupted by one or more (preferably less than 4) oxygen, sulphur,silicon atoms, or by silano or dialkylsilicon groups, or mixturesthereof.

The term “alkynyl” when used herein, means C₂ to C₁₀ alkynyl,preferably, C₁ to C₆ alkynyl, more preferably, C₁ to C₄ alkynyl andincludes ethynyl, propynyl, butynyl, pentynyl, and hexynyl groups.Unless otherwise specified, alkynyl groups may, when there is asufficient number of carbon atoms, be linear or branched, be saturatedor unsaturated, be cyclic, acyclic or part cyclic/acyclic, beunsubstituted, substituted or terminated by one or more substituentsselected from halo, cyano, nitro, OR¹⁹, OC(O)R²⁰, C(O)R²¹, C(O)OR²²,NR²³R²⁴, C(O)NR²⁵R²⁶, SR²⁹, C(O)SR³⁰, C(S)NR²⁷R²⁸, unsubstituted orsubstituted aryl, or unsubstituted or substituted Het, wherein R¹⁹ toR³⁰ are defined herein and/or be interrupted by one or more (preferablyless than 4) oxygen, sulphur, silicon atoms, or by silano ordialkylsilicon groups, or mixtures thereof.

The terms “aralkyl”, “alkaryl”, “arylenealkyl” or the like should, inthe absence of information to the contrary, be taken to be in accordancewith the above definition of “alkyl” as far as the alkyl or alk portionof the group is concerned.

The above Ar or aryl groups may be attached by one or more covalentbonds but references to “arylene” or “arylenealkyl” or the like hereinshould be understood as two covalent bond attachment but otherwise bedefined as Ar or aryl above as far as the arylene portion of the groupis concerned. References to “alkaryl”, “aralkyl” or the like should betaken as references to Ar or aryl above as far as the Ar or aryl portionof the group is concerned.

Halo groups with which the above-mentioned groups may be substituted orterminated include fluoro, chloro, bromo and iodo.

The term “Het”, when used herein, includes four- to twelve-membered,preferably four- to ten-membered ring systems, which rings contain oneor more heteroatoms selected from nitrogen, oxygen, sulfur and mixturesthereof, and which rings contain no, one or more double bonds or may benon-aromatic, partly aromatic or wholly aromatic in character. The ringsystems may be monocyclic, bicyclic or fused. Each “Het” groupidentified herein may be unsubstituted or substituted by one or moresubstituents selected from halo, cyano, nitro, oxo, alkyl (which alkylgroup may itself be unsubstituted or substituted or terminated asdefined herein) —OR¹⁹, —OC(O)R²³, —C(O)R²¹, —C(O)OR²², —N(R²³)R²⁴,—C(O)N(R²⁵)R²⁶, —SR²⁹, —C(O)SR³⁰ or —C(S)N(R²⁷)R²⁸ wherein R¹⁹ to R³⁰are as defined herein The term “Het” thus includes groups such asoptionally substituted azetidinyl, pyrrolidinyl, imidazolyl, indolyl,furanyl, oxazolyl, isoxazolyl, oxadiazolyl, thiazolyl, thiadiazolyl,triazolyl, oxatriazolyl, thiatriazolyl, pyridazinyl, morpholinyl,pyrimidinyl, pyrazinyl, quinolinyl, isoquinolinyl, piperidinyl,pyrazolyl and piperazinyl. Substitution at Het may be at a carbon atomof the Het ring or, where appropriate, at one or more of theheteroatoms.

“Het” groups may also be in the form of an N oxide.

The term hetero as mentioned herein means nitrogen, oxygen, sulfur ormixtures thereof.

The catalyst compounds of the present invention may act as a“heterogeneous” catalyst or a “homogeneous” catalyst, preferably, ahomogenous catalyst.

By the term “homogeneous” catalyst we mean a catalyst, i.e. a compoundof the invention, which is not supported but is simply admixed or formedin-situ with the reactants of the carbonylation reaction, preferably ina suitable solvent as described herein.

By the term “heterogeneous” catalyst we mean a catalyst, i.e. thecompound of the invention, which is carried on a support.

Where a compound of a formula herein (e.g. formula I) contains analkenyl group or a cycloalkyl moiety as defined, cis (E) and trans (Z)isomerism may also occur. The present invention includes the individualstereoisomers of the compounds of any of the formulas defined hereinand, where appropriate, the individual tautomeric forms thereof,together with mixtures thereof. Separation of diastereoisomers or cisand trans isomers may be achieved by conventional techniques, e.g. byfractional crystallisation, chromatography or H.P.L.C. of astereoisomeric mixture of a compound one of the formulas or a suitablesalt or derivative thereof. An individual enantiomer of a compound ofone of the formulas may also be prepared from a corresponding opticallypure intermediate or by resolution, such as by H.P.L.C. of thecorresponding racemate using a suitable chiral support or by fractionalcrystallisation of the diastereoisomeric salts formed by reaction of thecorresponding racemate with a suitable optically active acid or base, asappropriate.

Support and Dispersant

According to a further aspect, the present invention provides a processfor the carbonylation of an ethylenically unsaturated compound asdefined herein wherein the process is carried out with the catalystcomprising a support, preferably an insoluble support.

Preferably, the support comprises a polymer such as a polyolefin,polystyrene or polystyrene copolymer such as a divinylbenzene copolymeror other suitable polymers or copolymers known to those skilled in theart; a silicon derivative such as a functionalised silica, a silicone ora silicone rubber; or other porous particulate material such as forexample inorganic oxides and inorganic chlorides.

Preferably the support material is porous silica which has a surfacearea in the range of from 10 to 700 m²/g, a total pore volume in therange of from 0.1 to 4.0 cc/g and an average particle size in the rangeof from 10 to 500 μm. More preferably, the surface area is in the rangeof from 50 to 500 m²/g, the pore volume is in the range of from 0.5 to2.5 cc/g and the average particle size is in the range of from 20 to 200μm. Most desirably the surface area is in the range of from 100 to 400m²/g, the pore volume is in the range of from 0.8 to 3.0 cc/g and theaverage particle size is in the range of from 30 to 100 μm. The averagepore size of typical porous support materials is in the range of from 10to 1000 Å. Preferably, a support material is used that has an averagepore diameter of from 50 to 500 Å, and most desirably from 75 to 350 Å.It may be particularly desirable to dehydrate the silica at atemperature of from 100° C. to 800° C. anywhere from 3 to 24 hours.

Suitably, the support may be flexible or a rigid support, the insolublesupport is coated and/or impregnated with the compounds of the processof the invention by techniques well known to those skilled in the art.

Alternatively, the compounds of the process of the invention are fixedto the surface of an insoluble support, optionally via a covalent bond,and the arrangement optionally includes a bifunctional spacer moleculeto space the compound from the insoluble support.

The compounds of the invention may be fixed to the surface of theinsoluble support by promoting reaction of a functional group present inthe compound of formula I with a complimentary reactive group present onor previously inserted into the support. The combination of the reactivegroup of the support with a complimentary substituent of the compound ofthe invention provides a heterogeneous catalyst where the compound ofthe invention and the support are linked via a linkage such as an ether,ester, amide, amine, urea, keto group.

The choice of reaction conditions to link a compound of the process ofthe present invention to the support depends upon the groups of thesupport. For example, reagents such as carbodiimides,1,1′-carbonyldiimidazole, and processes such as the use of mixedanhydrides, reductive amination may be employed.

According to a further aspect, the present invention provides the use ofthe process or catalyst of any aspect of the invention wherein thecatalyst is attached to a support.

Additionally, the bidentate ligand may be bonded to a suitable polymericsubstrate via at least one of the bridge substituents (including cyclicatoms), the bridging group X, the linking group A or the linking group Be.g.1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)benzenemay be bonded, preferably, via the 3, 4, 5 or 6 cyclic carbons of thebenzene group to polystyrene to give an immobile heterogeneous catalyst.

The use of stabilising compounds with the catalyst system may also bebeneficial in improving recovery of metal which has been lost from thecatalyst system. When the catalyst system is utilized in a liquidreaction medium such stabilizing compounds may assist recovery of thegroup 8, 9 or 10 metal.

Preferably, therefore, the catalyst system includes in a liquid reactionmedium a polymeric dispersant dissolved in a liquid carrier, saidpolymeric dispersant being capable of stabilising a colloidal suspensionof particles of the group 8, 9 or 10 metal or metal compound of thecatalyst system within the liquid carrier.

The liquid reaction medium may be a solvent for the reaction or maycomprise one or more of the reactants or reaction products themselves.The reactants and reaction products in liquid form may be miscible withor dissolved in a solvent or liquid diluent.

The polymeric dispersant is soluble in the liquid reaction medium, butshould not significantly increase the viscosity of the reaction mediumin a way which would be detrimental to reaction kinetics or heattransfer. The solubility of the dispersant in the liquid medium underthe reaction conditions of temperature and pressure should not be sogreat as to deter significantly the adsorption of the dispersantmolecules onto the metal particles.

The polymeric dispersant is capable of stabilising a colloidalsuspension of particles of said group 8, 9 or 10 metal or metal compoundwithin the liquid reaction medium such that the metal particles formedas a result of catalyst degradation are held in suspension in the liquidreaction medium and are discharged from the reactor along with theliquid for reclamation and optionally for re-use in making furtherquantities of catalyst. The metal particles are normally of colloidaldimensions, e.g. in the range 5-100 nm average particle size althoughlarger particles may form in some cases. Portions of the polymericdispersant are adsorbed onto the surface of the metal particles whilstthe remainder of the dispersant molecules remain at least partiallysolvated by the liquid reaction medium and in this way the dispersedgroup 8, 9 or 10 metal particles are stabilised against settling on thewalls of the reactor or in reactor dead spaces and against formingagglomerates of metal particles which may grow by collision of particlesand eventually coagulate. Some agglomeration of particles may occur evenin the presence of a suitable dispersant but when the dispersant typeand concentration is optimised then such agglomeration should be at arelatively low level and the agglomerates may form only loosely so thatthey may be broken up and the particles redispersed by agitation.

The polymeric dispersant may include homopolymers or copolymersincluding polymers such as graft copolymers and star polymers.

Preferably, the polymeric dispersant has sufficiently acidic or basicfunctionality to substantially stabilise the colloidal suspension ofsaid group 8, 9 or 10 metal or metal compound.

By substantially stabilise is meant that the precipitation of the group8, 9 or 10 metal from the solution phase is substantially avoided.

Particularly preferred dispersants for this purpose include acidic orbasic polymers including carboxylic acids, sulphonic acids, amines andamides such as polyacrylates or heterocycle, particularly nitrogenheterocycle, substituted polyvinyl polymers such as polyvinylpyrrolidone or copolymers of the aforesaid.

Examples of such polymeric dispersants may be selected frompolyvinylpyrrolidone, polyacrylamide, polyacrylonitrile,polyethylenimine, polyglycine, polyacrylic acid, polymethacrylic acid,poly(3-hydroxybutyricacid), poly-L-leucine, poly-L-methionine,poly-L-proline, poly-L-serine, poly-L-tyrosine,poly(vinylbenzenesulphonic acid) and poly(vinylsulphonic acid), acylatedpolyethylenimine. Suitable acylated polyethylenimines are described inBASF patent publication EP1330309 A1 and U.S. Pat. No. 6,723,882.

Preferably, the polymeric dispersant incorporates acidic or basicmoieties either pendant or within the polymer backbone. Preferably, theacidic moieties have a dissociation constant (pK_(a)) of less than 6.0,more preferably, less than 5.0, most preferably less than 4.5.Preferably, the basic moieties have a base dissociation constant(pK_(b)) being of less than 6.0, more preferably less than 5.0 and mostpreferably less than 4.5, pK_(a) and pK_(b) being measured in diluteaqueous solution at 18° C.

Suitable polymeric dispersants, in addition to being soluble in thereaction medium at reaction conditions, contain at least one acidic orbasic moiety, either within the polymer backbone or as a pendant group.We have found that polymers incorporating acid and amide moieties suchas polyvinylpyrollidone (PVP) and polyacrylates such as polyacrylic acid(PAA) are particularly suitable. The molecular weight of the polymerwhich is suitable for use in the invention depends upon the nature ofthe reaction medium and the solubility of the polymer therein. We havefound that normally the average molecular weight is less than 100,000.Preferably, the average molecular weight is in the range 1,000-200,000,more preferably, 5,000-100,000, most preferably, 10,000-40,000 e.g. Mwis preferably in the range 10,000-80,000, more preferably 20,000-60,000when PVP is used and of the order of 1,000-10,000 in the case of PAA.

The effective concentration of the dispersant within the reaction mediumshould be determined for each reaction/catalyst system which is to beused.

The dispersed group 8, 9 or 10 metal may be recovered from the liquidstream removed from the reactor e.g. by filtration and then eitherdisposed of or processed for re-use as a catalyst or other applications.In a continuous process the liquid stream may be circulated through anexternal heat-exchanger and in such cases it may be convenient to locatefilters for the palladium particles in these circulation apparatus.

Preferably, the polymer:metal mass ratio in g/g is between 1:1 and1000:1, more preferably, between 1:1 and 400:1, most preferably, between1:1 and 200:1. Preferably, the polymer:metal mass ratio in g/g is up to1000, more preferably, up to 400, most preferably, up to 200.

Preferably, the carbonylation reaction is an anaerobic reaction. Inother words, typically the reaction takes place generally in the absenceof oxygen.

Conveniently, the process of the invention may utilise highly stablecompounds under typical carbonylation reaction conditions such that theyrequire little or no replenishment. Conveniently, the process of theinvention may have a high rate for the carbonylation reaction.Conveniently, the process of the invention may promote high conversionrates, thereby yielding the desired product in high yield with little orno impurities. Consequently, the commercial viability of thecarbonylation reaction may be increased by employing the process of theinvention. It is especially advantageous that the process of theinvention provides a carbonylation reaction with a high TON number.

It will be appreciated that any of the features set forth in the firstaspect of the invention may be regarded as preferred features of thefurther aspects of the present invention and vice versa.

The invention will now be described and illustrated by way of thefollowing non-limiting examples and comparative examples

PREPARATIVE EXAMPLES Preparation of Cyclic Sulphate of1,2-Benzenedimethanol (3)

The method employed for the synthesis of phosphine ligands of thederivatives of the examples starts with the synthesis of the cyclicsulphate (3). The cyclic sulphate compound is formed in a two stepsynthesis. The commercially available di-alcohol 1,2-benzenedimethanol(1) (which can also be prepared by the lithium aluminium hydridereduction of phthalic acid) was reacted with thionyl chloride (SOCl₂) indichloromethane to give the cyclic sulphite complex (2). The cyclicsulphite complex was then oxidised with sodium periodate and rutheniumtrichloride to give the cyclic sulphate complex (3).

Experimental General

Unless stated to the contrary all manipulations were performed under anatmosphere of Nitrogen using standard Schlenk line, cannula and gloveboxtechniques. All NMR experiments were performed using CDCl₃ as thesolvent.

Preparation of Cyclic Sulphate (3)

The dialcohol (1) (21.2 g, 153 mmol) was partially dissolved indichloromethane (250 ml). To this was added thionyl chloride (13.8 ml,189 mmol) slowly. This gave a large volume of gas evolution. Theresultant solution was then heated to reflux (50° C.) for 90 minutes.The resultant solution was then cooled to room temperature and stirredovernight. At this point the cyclic sulfite complex (2) had been formed.The solvent was then removed under vacuum to give a pale brown oil. Thecyclic sulfite was then diluted with dichloromethane (100 ml),acetonitrile (100 ml) and water (150 ml). To the resultant biphasicsolution was added sodium periodate (65.3 g, 306 mmol) and Rutheniumtrichloride hydrate (300 mg). The resultant suspension was then stirredat room temperature for one hour during this time a large volume ofwhite precipitate was formed. The final suspension was diluted withwater (100 ml) and ether (100 ml) added. The organic layer was collectedby separation and the aqueous residues washed with ether (2*100 ml). Thecombined organic extracts were then washed with water (2*200 ml) beforebeing dried over sodium sulphate. The organic extracts were thenfiltered through filter paper containing celite. This gave anoff-colourless solution. The solvent was then removed under vacuum togive an off white solid. The solid was stored in the freezer at −20° C.Yield=24.6 g, 80%. ¹H NMR (500 MHz, CDCl₃, δ), 7.46 (m, 2H, Ph), 7.38(m, 2H, Ph), 5.44 (s, 4H, CH₂) ppm.

Synthesis of1-(di-tert-butyl)phosphinomethyl)-2-((di-pyridin-2-yl)phosphinomethyl)benzenePreparation of Tris(pyridin-2-yl)phosphine

2-Bromopyridine (100 g, 633 mmol) was added dropwise over 30 min to astirred solution of Bu^(n)Li (2.5M in hexane, 253 ml, 633 mmol) in Et₂O(300 ml) at −78° C. in a 1 L flask. This mixture was stirred at −78° C.for 1 h, then PCl₃ (18.4 ml, 211 mmol) added dropwise over 30 min withstirring. The resultant mixture was then stirred for 30 minutes at −78°C. before being allowed to warm up to room temperature and then stirredat room temperature for one hour. The resultant tan mixture was thendried under vacuum and water (300 ml, degassed with nitrogen gas for 30minutes) added. Chloroform (400 ml) was then added. The biphasic mixturewas then stirred for 30 minutes and then the lower (organic phase) wascannula transferred into a clean Schlenk flask. The solvent was thenremoved under vacuum to give a sticky brown/red solid. To this was addedpentane (50 ml) and the pentane stirred into the mixture, this gave abrown/orange solid. The pentane soluble material was removed by cannulaand the pentane washing repeated. Again the pentane soluble material wasremoved by cannula. The residue was then dried under vacuum before beingsuspended in ethanol (20 ml). The ethanol suspension was then heated upto 80° C. which gave a dark red solution. This was then allowed to coolto room temperature and orange/yellow crystals started to form. Thesolution was then placed in the freezer at −20° C. overnight. This gavea large amount of red/orange solid. The ethanol soluble material wasthen removed by cannula and the solid dried under vacuum. This gave asticky orange solid. Yield=22.4 g, 40%. ³¹P{¹H}NMR (121 MHz, CDCl3) ä:−0.42 (s, PPy₂).

Preparation of Bis(pyridin-2-yl)phosphine (Py₂PH)

The tris(pyridin-2-yl)phosphine (22.4 g, 85 mmol) was suspended in THF(400 ml). To this were added lithium granules (5.0 g, 720 mmol). Themixture was then stirred at room temperature for four hours. This gavean intense red solution. The solution was then filtered into a cleanSchlenk flask to remove any un-reacted lithium metal. The solvent wasthen removed under vacuum and water (100 ml, degassed with nitrogen gasfor 20 minutes) added. Ether (400 ml) was then added and the biphasicsolution stirred for 20 minutes. The upper (organic) phase was thencannula transferred into a clean Schlenk flask and then dried undervacuum. This gave dark orange/red oil. Yield=15.1 g, 94% ³¹P{¹H}NMR (121MHz, CDCl3) ä; −33.8 (s, PPy₂).

Preparation of di-tert-butylphosphine borane

Di-tert-butylphosphine chloride (34 g, 188.41 mmol) was added to aSchlenk flask followed by diethyl ether (200 ml). The ether solution wascooled in a cold water bath and LiAlH₄ (1M in diethyl ether, 100 ml, 100mmol) was added slowly. This gave a yellow suspension which was stirredat room temperature overnight. The suspension was quenched by theaddition of water (50 ml, degassed with nitrogen for 20 minutes). Thisgave a biphasic solution. The upper (organic layer) was cannulatransferred into a clean Schlenk and the aqueous residues washed with afurther 100 ml of ether. The ether extracts were combined and dried withsodium sulphate. The ether extracts were then cannula transferred into aclean Schlenk and the ether removed by distillation. This gave acolourless oil. The colourless oil was then diluted with THF (200 ml)and cooled to 0° C., to this was added BH₃ in THF (1M solution, 250 ml,250 mmol). The resultant solution was then stirred at room temperatureovernight. The solvent was then removed under vacuum to give a whitecrystalline solid which was then isolated in the glovebox. Yield=22.1 g,73% yield. ³¹P {¹H}NMR (80 MHz, CDCl₃, δ): δ 49.23 ppm (multiplet).

Synthesis of1-(di-tert-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)benzene

A 2.5M solution of Bu^(n)Li (83 mL, 207.5 mmol) in hexanes was added toa solution of ^(t)Bu₂PH.BH₃ (33.2 g, 207.5 mmol) in THF (250 mL) at 0°.The mixture was allowed to reach room temperature then stirred for 30min. After cooling to −78° C., it was added dropwise over 10 min to apre-cooled (−78° C.) solution of the cyclic sulfate (1,2-C₆H₄(CH₂O)₂SO₂)(41.5 g, 207.5 mmol) in THF (300 mL). The mixture was stirred for 30 minat −78° C. and then stirred for 30 min at room temperature. Aftercooling the mixture to −78° C., it was treated with a solution of Py₂PLi{prepared from Py₂PH (39 g, 207.5 mmol) in THF (250 mL) and Bu^(n)Li (83ml of a 2.5M solution in hexane, 207.5 mmol) at −78° C.}. The mixturewas allowed to warm to room temperature and then stirred overnight. Thesolvent was removed under reduced pressure and the residue wasre-dissolved in Et₂O (500 mL). The solution was then quenched with water(200 mL). The biphasic mixture was then stirred at room temperature for30 minutes before the organic (upper) phase was cannula transferred intoa clean Schlenk flask. The solvent was then removed under vacuum to givea brown sticky solid. The solid was dissolved in TBME (600 ml) andtetrafluoroboric acid diethyl ether complex (1245 mmol, 171 ml) was thenadded. This gave the immediate formation of an orange precipitate. Themixture was then heated to reflux for 16 hours. The solvent was thenremoved under vacuum and the residue treated with a solution ofpotassium hydroxide (80 g, 1426 mmol) in water (300 ml, degassed withnitrogen gas for 30 minutes). Pentane (500 ml) was then added and thebiphasic mixture rapidly stirred for thirty minutes. The upper phase(organic) was then cannula transferred into a clean Schlenk and thesolvent removed under vacuum. This gave a sticky viscous red/orange oil,yield 29.4 g, 32% ³¹P{¹H}NMR (121 MHz, CDCl₃) ä: −6.5 (s, PPy); 28.5 (s,PBu^(t))

Synthesis of Pyridylphenylphosphine

A solution of Cl₂PPh (30 mL, 220 mmol) in Et₂O (800 mL) in a 1 L Schlenkflask was cooled to −78° C. and a solution of HNEt₂ (46 mL, 440 mmol)added through a dropping funnel over 30 min with stirring. The solutionwas allowed to rise to room temperature and stood overnight. Theresulting yellow solution was cannula transferred into a clean Schlenkflask and the solvent removed under vacuum. To the solid residue wasadded ether (500 ml) and the mixture rapidly stirred for 1 hour and thenstood overnight. The ether extracts were then combined and the driedunder vacuum. This gave pale oil. The yellow oil was then dissolved inether (500 ml) and a solution of LiPy {prepared by adding BrPy (21 mL,220 mmol) to a solution of BuLi (88 mL of a 2.5 M solution in hexane) inEt₂O (100 mL) dropwise over 30 min at −78° C., the solution was thenstirred for 1 h} was added via a cannula over 30 min. The solution wasallowed to reach room temperature and was then stirred overnight. Thisgave a pale brown suspension. HCl (110 mL of a 2 M solution in Et₂O) wasadded over 20 mins with vigorous stirring, generating a large quantityof pale brown precipitate. Further HCl (110 mL of a 2 M solution inEt₂O) was added. The suspension was then allowed to stand and the yellowsolution cannula transferred into a clean Schlenk flask. The brownprecipitate was washed again with THF (500 mL) and the washings combinedbefore removing the THF under vacuum leaving a red/orange solid. Thesolid was then dissolved in THF (300 mL) then added to an ice cooledsolution of magnesium powder (9 g) in THF (100 mL) over 30 mins withstirring. The solution was kept under ice cooling for a further 30 min,then allowed to rise to room temperature and stirring overnight. Thesolution was filtered to remove excess magnesium and quenched with water(100 mL, degassed with nitrogen gas for 20 minutes). The organic layerwas then cannula transferred into a clean Schlenk flask and then driedunder vacuum to give viscous orange oil, yield=15.1 g, 36%. ³¹P NMR (121MHz, CDCl₃) ä: −37.79 (d, J_(PH)=222 Hz).

Synthesis of1-(di-tert-butylphosphinomethyl)-2-pyridin-2-ylphenylphosphinomethyl)benzene

A 2.5M solution of Bu^(n)Li (32.1 mL, 80.2 mmol) in hexanes was added toa solution of ^(t)Bu₂PH.BH₃ (12.8 g, 80.2 mmol) in THF (150 mL) at 0°.The mixture was allowed to reach room temperature then stirred for 30min. After cooling to −78° C., it was added dropwise over 10 min to apre-cooled (−78° C.) solution of the cyclic sulfate (1,2-C₆H₄(CH₂O)₂SO₂)(16.0 g, 80.2 mmol) in THF (200 mL). The mixture was stirred for 30 minat −78° C. and then stirred for 30 min at room temperature. Aftercooling the mixture to −78° C., it was treated with a solution ofPyPhPLi {prepared from PyPhPH (15.1 g, 80.2 mmol) in THF (100 mL) andBu^(n)Li (32.1 ml of a 2.5M solution in hexane, 207.5 mmol) at −78° C.}.The mixture was allowed to warm to room temperature and then stirredovernight. The solvent was removed under reduced pressure and theresidue was re-dissolved in Et₂O (500 mL). The solution was thenquenched with water (200 mL). The biphasic mixture was then stirred atroom temperature for 30 minutes before the organic (upper) phase wascannula transferred into a clean Schlenk flask. The solvent was thenremoved under vacuum to give a brown/orange sticky solid. The solid wasdissolved in TBME (600 ml) and tetrafluoroboric acid diethyl ethercomplex (481 mmol, 66 ml) was then added. This gave the immediateformation of an orange precipitate. The mixture was then heated toreflux for 16 hours. The solvent was then removed under vacuum and theresidue treated with a solution of potassium hydroxide (40 g, 713 mmol)in water (300 ml, degassed with nitrogen gas for 30 minutes). Pentane(500 ml) was then added and the biphasic mixture rapidly stirred forthirty minutes. The upper phase (organic) was then cannula transferredinto a clean Schlenk flask and the solvent removed under vacuum. Thisgave a viscous orange oil, yield=7.9 g, 23% ³¹P{¹H}NMR (121 MHz, CDCl₃)ä: −10.0 (s, PPyPh); 28.2 (s, PBu^(t))

CARBONYLATION EXAMPLES General

Carbonylation is carried out as follows and the results with the ligandsof examples and comparative examples are shown in tables.

Experimental 1.0 Reactions using1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)benzene(TPhos) and (di-t-butylphosphinomethyl)benzene (Alpha) withTrifluoroacetic acid (TFA)

Using standard Schlenk line techniques, reaction solutions were preparedby dissolving 7.7 mg Pd₂(dba)₃ (1.46×10⁻⁵ moles Pd) and either 28.9 mg(di-t-butylphosphinomethyl)benzene (Alpha) (7.29×10⁻⁵ moles) or 31.8 mg1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)benzene(TPhos) (7.29×10⁻⁵ moles) dissolved in a 70:30% w/w solvent compositionof methyl propionate and methanol, in a total solution volume of 300 ml.The palladium and ligand were allowed to complex before the addition oftrifluoroacetic acid (TFA) completed the preparation of the catalystsolution.

The catalytic solution was added to the pre-evacuated autoclave and thereactants were heated to 100° C. with stirring at 1000 rpm. Next thereaction vessel was pressurised with 8 bars of ethene above the solventvapour pressure (2.3 bar at 100° C.), and the catalyst solution wasstirred for 20 mins. After pre-treatment with ethene the reaction wasinitiated by pressurising the reactor to 12.3 bar with a 1:1 molarmixture of CO and ethene, to afford an initial 9:1 gas phase molar ratioof ethylene:CO. The total reaction pressure (12.3 bar) was maintainedthroughout the batch study with the use of a Tescom regulatory valveattached to a 1:1 molar CO/ethene 10 L reservoir. Both the reaction TONand rate can be obtained by measuring the drop in the reservoir pressureand assuming ideal gas behaviour and 100% selectivity for methylpropionate. After the reaction period, the autoclave was cooled andvented.

TABLE 1 Summary of 1.0 conditions. Catalyst Conc^(n) (mol · dm⁻³) 4.90 ×10⁻⁵ Total ligand(L₂)/Pd 5:1 Total H⁺/Pd x:1 see table 5 Pressure (bar)12.3 Temperature (° C.) 100 Headspace C₂H₄/CO 9:1 L₂ Ligand H⁺ PropionicAcid

2.0 Reactions using1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)benzene(TPhos) and Methanesulphonic acid (MSA)

Using standard Schlenk line techniques, reaction solutions were preparedby dissolving 7.7 mg Pd₂(dba)₃ (1.46×10⁻⁵ moles Pd) and 31.8 mg1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)benzene(TPhos) (7.29×10⁻⁵ moles) dissolved in a solvent composition of methylpropionate and methanol which was varied between 90:10% w/w and 50:50%w/w. The total solution volume was kept constant (300 ml). The palladiumand ligand were allowed to complex before the addition of 430 μl(6.56×10⁻³ moles) methanesulphonic acid (MSA) completed the preparationof the catalyst solution. The catalytic solution was added to thepre-evacuated autoclave and the reactants were heated to 100° C. withstirring at 1000 rpm. Next the reaction vessel was pressurised with 8bars of ethene above the solvent vapour pressure (2.3 bar at 100° C.),and the catalyst solution was stirred for 20 mins. After pre-treatmentwith ethene the reaction was initiated by pressurising the reactor to12.3 bar with a 1:1 molar mixture of CO and ethene, to afford an initial9:1 gas phase molar ratio of ethylene:CO. The total reaction pressure(12.3 bar) was maintained throughout the batch study with the use of aTescom regulatory valve attached to a 1:1 molar CO/ethene 10 Lreservoir. Both the reaction TON and rate can be obtained by measuringthe drop in the reservoir pressure and assuming ideal gas behaviour and100% selectivity for methyl propionate. After the reaction period, theautoclave was cooled and vented.

TABLE 2 Summary of 2.0 conditions. Catalyst Conc^(n) (mol · dm⁻³) 4.90 ×10⁻⁵ Total L₂/Pd 5:1 Total H⁺/Pd 450:1  Pressure (bar) 12.3 Temperature(° C.) 100 Headspace C₂H₄/CO 9:1 L₂ Ligand H⁺ Propionic Acid

3.0 Initial Reactions using1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)benzene(TPhos) and (di-t-butylphosphinomethyl)benzene (Alpha) with Propionicacid (PA)

Using standard Schlenk line techniques, reaction solutions were preparedby dissolving 77 mg Pd₂(dba)₃ (1.46×10⁻⁴ moles Pd) and either 289 mg(di-t-butylphosphinomethyl)benzene (7.29×10⁻⁴ moles) or 318 mg TPhos(7.29×10⁻⁴ moles) dissolved in a 70:30 w/w solvent composition of methylpropionate and methanol, in a total solution volume of 300 ml. Thepalladium and ligand were allowed to complex before the addition of 70ml (9.33×10⁻¹ moles) propionic acid (PA). The catalytic solution wasadded to the pre-evacuated autoclave and the reactants were heated to100° C. with stirring at 1000 rpm. Next the reaction vessel waspressurised with 8 bars of ethene above the solvent vapour pressure (2.3bar at 100° C.), and the catalyst solution was stirred for 20 mins.After pre-treatment with ethene the reaction was initiated bypressurising the reactor to 12.3 bar with a 1:1 molar mixture of CO andethene, to afford an initial 9:1 gas phase molar ratio of ethylene:CO.The total reaction pressure (12.3 bar) was maintained throughout thebatch study with the use of a Tescom regulatory valve attached to a 1:1molar CO/ethene 10 L reservoir. Both the reaction TON and rate can beobtained by measuring the drop in the reservoir pressure and assumingideal gas behaviour and 100%; selectivity for methyl propionate. Afterthe reaction period, the autoclave was cooled and vented.

TABLE 3 Summary of 3.0 conditions. Catalyst Conc^(n) (mol · dm⁻³) 4.90 ×10⁻⁴ Total L₂/Pd 5:1 Total H⁺/Pd ~6400:1   Pressure (bar) 12.3Temperature (° C.) 100 Headspace C₂H₄/CO 9:1 L₂ Ligand H⁺ Propionic Acid

4.0 Further Specific Reactions using1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)benzene(TPhos) and (di-t-butylphosphinomethyl)benzene (Alpha) with Propionicacid (PA)

Using standard Schlenk line techniques, reaction solutions were preparedby dissolving 77 mg Pd₂(dba)₃ (1.46×10⁻⁴ moles Pd) and either 289 mg(di-t-butylphosphinomethyl)benzene (7.29×10⁻⁴ moles) or 318 mg TPhos(7.29×10⁻⁴ moles) dissolved in a 70:30 w/w solvent composition of methylpropionate and methanol, in a total solution volume of 300 ml. Thepalladium and ligand were allowed to complex before the addition ofpropionic acid (PA). The catalytic solution was added to thepre-evacuated autoclave and the reactants were heated to 100° C. withstirring at 1000 rpm. Next the reaction vessel was pressurised with 8bars of ethene above the solvent vapour pressure (2.3 bar at 100° C.),and the catalyst solution was stirred for 20 mins. After pre-treatmentwith ethene the reaction was initiated by pressurising the reactor to12.3 bar with a 1:1 (gas molar ratio) mixture of CO and ethene, toafford an initial 9:1 gas molar ratio of ethylene:CO in the gas phase ofthe reactor. The total reaction pressure (12.3 bar) was maintainedthroughout the batch study with the use of a Tescom regulatory valveattached to a 1:1 gas molar ratio CO/ethene 10 L reservoir. Both thereaction TON and rate can be obtained by measuring the drop in thereservoir pressure and assuming ideal gas behaviour and 100% selectivityfor methyl propionate. After the reaction period, the autoclave wascooled and vented.

TABLE 4 Summary of 4.0 conditions. Catalyst Conc^(n) (mol · dm⁻³) 4.90 ×10⁻⁴ Total L₂/Pd 5:1 Total H⁺/Pd x:1 see table 8 Pressure (bar) 12.3Temperature (° C.) 100 Headspace C₂H₄/CO (molar ratio) 9:1 L₂ Ligand H⁺Propionic Acid

Results 1.0 Results of Reactions using1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)benzene(TPhos) and (di-t-butylphosphinomethyl)benzene (Alpha) withTrifluoroacetic acid (TFA)

The results are presented in Table 5 and Table 6. TPhos has been shownto outperform (di-t-butylphosphinomethyl)benzene comparative example bya 3 to 4 fold margin in the relatively weak acid TFA.

TABLE 5 Example 1 Example 2 Example 3 TPhos 1000 eq TPhos 2000 eq TPhos4500 eq of TFA of TFA of TFA (1.083 cm³) (2.166 cm³) (4.870 cm³) Rate46602 47611 41386 (mol MeP/mol Pd/hr) TON 15570 15378 21038 (molesMeP/mole Pd)

TABLE 6 Comparative Comparative Example 4 Example 5 Alpha 1000 eq Alphaof TFA 4500 eq of TFA (1.083 cm³) (4.870 cm³) Rate (mol MeP/mol 191110696 Pd/hr) TON moles MeP/mole 3407 11038 Pd

2.0 Results of Reactions using1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)benzene(TPhos) and Methanesulphonic acid (MSA)

The results are presented in Table 7

TABLE 7 TON MeP/MeOH Initial Rate moles MeP/mole % w/w (mol MeP/molPd/hr) Pd 50/50 68557 59137 70/30 39771 33456 80/20 23524 23397 90/1011496 10151

The data in table 7 show that the ligand1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)benzene(TPhos) has good activity when used with methanesulphonic acid.

3.0 Initial Propionic Acid Reactions

The results of the initial study conducted using 1.46×10⁻⁴ moles Pd anda Palladium concentration of 3.90×10⁻⁴ mol·dm⁻³ were that TPhos wasfound to display higher rates and dramatically improved TON comparedwith (di-t-butylphosphinomethyl)benzene in propionic acid (PA).

4.0 Results of further reactions using1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)benzene(TPhos) and (di-t-butylphosphinomethyl)benzene (Alpha) with Propionicacid (PA)

TABLE 8 Example 3 Example 1 Example 2 TPhos TPhos TPhos 12854 mole eq3213 mole eq 6427 mole eq of PA of PA (35 cm³) of PA (70 cm³) (140 cm³)to to Pd to Pd Pd Rate 474 3286 3300 (mol MeP/mol Pd/hr) TON 880 23402376 (moles MeP/mole Pd)

TABLE 9 Comparative Comparative Example 4 Example 5 Alpha Alpha 6427mole eq 12854 mole eq of PA of PA (70 cm³) to Pd (140 cm³) to Pd Rate(mol MeP/mol 557 1128 Pd/hr) TON moles MeP/mole 560 1230 Pd

The reader's attention is directed to all papers and documents which arefiled concurrently with or previous to this specification in connectionwith this application and which are open to public inspection with thisspecification, and the contents of all such papers and documents areincorporated herein by reference.

All of the features disclosed in this specification (including anyaccompanying claims, abstract and drawings), and/or all of the steps ofany method or process so disclosed, may be combined in any combination,except combinations where at least some of such features and/or stepsare mutually exclusive.

Each feature disclosed in this specification (including any accompanyingclaims, abstract and drawings), may be replaced by alternative featuresserving the same, equivalent or similar purpose, unless expressly statedotherwise. Thus, unless expressly stated otherwise, each featuredisclosed is one example only of a generic series of equivalent orsimilar features.

The invention is not restricted to the details of the foregoingembodiment(s). The invention extends to any novel one, or any novelcombination, of the features disclosed in this specification (includingany accompanying claims, abstract and drawings), or to any novel one, orany novel combination, of the steps of any method or process sodisclosed.

The invention claimed is:
 1. A bidentate ligand of formula (I)

wherein: A and B each independently represent a direct bond or a loweralkylene linking group having from 1 to 10 carbons; R represents ahydrocarbyl aromatic structure having at least one aromatic ring whichis part of a metallocene complex and to which Q¹ and Q² are each linked,through B and A, respectively, on available adjacent atoms of the atleast one aromatic ring; the groups X³ and X⁴ independently representunivalent radicals of up to 30 atoms having at least one tertiary carbonatom or X³ and X⁴ together form a bivalent radical of up to 40 atomshaving at least two tertiary carbon atoms wherein each said univalent orbivalent radical is joined via said at least one or two tertiary carbonatoms respectively to the respective atom Q¹; the group X¹ is defined asa univalent hydrocarbyl radical of up to 30 atoms containing at leastone nitrogen atom having a pKb in dilute aqueous solution at 18° C. ofbetween 4 and 14 wherein the said at least one nitrogen atom isseparated from the Q² atom by between 1 and 3 carbon atoms, wherein thegroup X¹ is selected from the group consisting of an aromatic nitrogenheterocycle having 3-14 ring atoms, aziridine, azirine, azetidine,azete, pyrrolidone, piperidine, azepane, azepine, azocane, azocineimidazolidine, pyrazolidine, imidazoline, pyrazoline, piperazine,hexahydro-pyrimidine, hexahydro-pyridazine, and pyrrolidine radicals;the group X² is defined as X¹, X³ or X⁴ or represents a univalentradical of up to 30 atoms having at least one primary, secondary oraromatic ring carbon atom wherein each said univalent radical is joinedvia said at least one primary, secondary or aromatic ring carbon atom(s)respectively to the respective atom Q²; and Q¹ and Q² each independentlyrepresent phosphorus, arsenic or antimony.
 2. The bidentate ligandaccording to claim 1, wherein X² is the same group as X¹.
 3. Thebidentate ligand according to claim 1 selected from the group consistingof1-(di-tert-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)ferrocene,1-(1-adamantyltert-butyl-phosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-pyridin-2-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-pyridin-2-ylphosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)ferrocene,1-(di-pyridin-2-yl-phosphinomethyl)-2,3-bis-(ditertbutylphosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1′-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-ylphosphinomethyl)-1-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-tbutylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1′-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-2-yl-phosphinomethyl)4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1′-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1′-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-tbutylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1′-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1′-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1′-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1′-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-tbutylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1′-t-butylferrocene,1-(P,P adamantyl, t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P adamantyl, t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-phenylferrocene,t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1-phenylferrocene,1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P adamantyl, t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P adamantyl, t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1′-(trimethylsilyl)ferrocene,1-(P,P adamantyl, t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P adamantyl, t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1′-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-4-t butylferrocene,1-(P,P-adamantyl, t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)-1′-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-diphenyl-methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-2-ylphosphinomethyl)-4-phenyl-methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-2-ylphosphinomethyl)-1′-phenyl-methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-bis(trimethylsilyl)-methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-2-ylphosphinomethyl)-4-(trimethylsilyl)-methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-2-ylphosphinomethyl)-1′-(trimethylsilyl)-methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)-methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)-methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-2-yl-phosphinomethyl)-1′-(2′-phenylprop-2′-yl)-methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)-methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-2-yl-phosphinomethyl)-4-t-butyl-methylferrocene,and1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-2-yl-phosphinomethyl)-1′-t-butyl-methylferrocene.4. The bidentate ligand according to claim 1 wherein A and B aremethylene.
 5. The bidentate ligand according to claim 1, wherein Q¹ andQ² are each phosphorous.
 6. The bidentate ligand according to claim 1being1-(di-tert-butylphosphinomethyl)-2-(pyridin-2-yl-phenylphosphinomethyl)ferrocene.7. The bidentate ligand according to claim 1 being1-(di-t-butylphosphinomethyl)-2-(di-pyridin-2-yl-phosphinomethyl)ferrocene.8. The bidentate ligand according to claim 1 selected from the groupconsisting of1-(di-tert-butylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)ferrocene,1-(1-adamantyl-tert-butyl-phosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-pyridin-3-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-pyridin-3-yl-phosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-diphenylmethylferrocene,1(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-3-yl-phosphinomethyl)-4-phenyl-methylferrocene,1(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-3-yl-phosphinomethyl)-4-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-(di-t-butyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyridin-3-yl-phosphinomethyl)-4-t-butylmethylferrocene,1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-phenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P-adamantly-t-butyl-phosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantly-t-butyl-phosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,and1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyridin-3-yl-phosphinomethyl)-4-t-butylferrocene.9. The bidentate ligand according to claim 1 selected from the groupconsisting of1-(di-tert-butylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)ferrocene,1-(1adamantyl-tert-butyl-phosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-piperidin-2-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-piperidin-2-yl-phosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-diphenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-2-yl-phosphinomethyl)-4-phenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-2-yl-phosphinomethyl)-4-t-butylmethylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P-adamantyl,t-butyl-phosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,and1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-2-yl-phosphinomethyl)-4-t-butylferrocene.10. The bidentate ligand according to claim 1 selected from the groupconsisting of1-(di-tert-butylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)ferrocene,1-(1adamantyl-tert-butyl-phosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-piperidin-3-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-piperidin-3-yl-phosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-diphenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-3-yl-phosphinomethyl)-4-phenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-3-yl-phosphinomethyl)-4-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-(di-t-butyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperidin-3-yl-phosphinomethyl)-4-t-butylmethylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-phenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,and adamantyl, t1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperidin-3-yl-phosphinomethyl)-4-t-butylferrocene.11. The bidentate ligand according to claim 1 selected from the groupconsisting of1-(di-tert-butylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)ferrocene,1-(1-adamantyltert-butyl-phosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-pyrrol-2-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-pyrrol-2-yl-phosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-diphenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-2-yl-phosphinomethyl)-4-phenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-2-yl-phosphinomethyl)-4-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-(di-t-butyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-2-yl-phosphinomethyl)-4-t-butylmethylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-phenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,and1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-2-yl-phosphinomethyl)-4-t-butylferrocene.12. The bidentate ligand according to claim 1 selected from the groupconsisting of1-(di-tert-butylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)ferrocene,1-(1-adamantyltert-butyl-phosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-pyrrol-3-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-pyrrol-3-yl-phosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-diphenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-3-yl-phosphinomethyl)-4-phenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-3-yl-phosphinomethyl)-4-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-(di-t-butyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrol-3-yl-phosphinomethyl)-4-t-butylmethylferrocene,1-(P,P adamantyl, t-butylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-phenylferrocene,1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,and1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrol-3-yl-phosphinomethyl)-4-t-butylferrocene.13. The bidentate ligand according to claim 1 selected from the groupconsisting of1-(di-tert-butylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)ferrocene,1-(1adamantyl-tert-butyl-phosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-pyrrolidin-2-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-pyrrolidin-2-yl-phosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-diphenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-phenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-t-butylmethylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,and adamantyl,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrolidin-2-yl-phosphinomethyl)-4-t-butylferrocene.14. The bidentate ligand according to claim 1 selected from the groupconsisting of1-(di-tert-butylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)ferrocene,1-(1adamantyl-tert-butyl-phosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-pyrrolidin-3-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-pyrrolidin-3-yl-phosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-diphenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-phenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-(di-t-butyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-t-butylmethylferrocene,1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-phenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,and adamantyl, 1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-pyrrolidin-3-yl-phosphinomethyl)-4-t-butylferrocene.15. The bidentate ligand according to claim 1 selected from the groupconsisting of1-(di-tert-butylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)ferrocene,1-(1adamantyl-tert-butyl-phosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-quinolin-2-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-quinolin-2-yl-phosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-diphenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-quinolin-2-yl-phosphinomethyl)-4-phenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-quinolin-2-yl-phosphinomethyl)-4-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-quinolin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-quinolin-2-yl-phosphinomethyl)-4-t-butylmethylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-Quinolin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-quinolin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,and1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-Quinolin-2-yl-phosphinomethyl)-4-t-butylferrocene.16. The bidentate ligand according to claim 1 selected from the groupconsisting of1-(di-tert-butylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)ferrocene,1-(1adamantyl-tert-butyl-phosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-pyrazin-2-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-pyrazin-2-yl-phosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-diphenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrazin-2-yl-phosphinomethyl)-4-phenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrazin-2-yl-phosphinomethyl)-4-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrazin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrazin-2-yl-phosphinomethyl)-4-t-butylmethylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,and1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrazin-2-yl-phosphinomethyl)-4-t-butylferrocene.17. The bidentate ligand according to claim 1 selected from the groupconsisting of1-(di-tert-butylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)ferrocene,1-(1adamantyl-tert-butyl-phosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-piperazin-2-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-piperazin-2-yl-phosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-diphenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperazin-2-yl-phosphinomethyl)-4-phenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperazin-2-yl-phosphinomethyl)-4-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperazin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-piperazin-2-yl-phosphinomethyl)-4-t-butylmethylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,and adamantyl, 1-(P,P-adamantyl-t-butylphosphinomethyl)-2-(di-piperazin-2-yl-phosphinomethyl)-4-t-butylferrocene.18. The bidentate ligand according to claim 1 selected from the groupconsisting of1-(di-tert-butylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(1adamantyl-tert-butyl-phosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-pyrimidin-2-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-pyrimidin-2-yl-phosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-diphenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-phenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-t-butylmethylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P-adamantyl,t-butyl-phosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,and1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-pyrimidin-2-yl-phosphinomethyl)-4-t-butylferrocene.19. The bidentate ligand according to claim 1 selected from the groupconsisting of1-(di-tert-butylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(di-tert-pentylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(diadamantylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(di-3,5-dimethyladamantylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(di-5-tert-butyladamantylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(1adamantyl-tert-butyl-phosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one)-2-(di-hexahydro-pyrimidin-2-yl-phosphino)-1,2-dimethylferrocene,1-(2-(phospha-adamantyl))-2-(di-hexahydro-pyrimidin-2-yl-phosphino)-1,2-dimethylferrocene,1-(dicongressylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-t-butylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-di-t-butylferrocene,1-(di-t-butylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(2-phosphinomethyl-adamantyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5diphenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(di-adamantylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,1-(di-adamantylphosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-t-butylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-diphenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-phenylmethylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)methylferrocene,1-(P-(2,2,6,6-tetramethyl-phospha-cyclohexan-4-one))-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-t-butylmethylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-diphenylferrocene,1-(P,P-adamantly-t-butyl-phosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-phenylferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-bis-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-(trimethylsilyl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-di-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-(2′-phenylprop-2′-yl)ferrocene,1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4,5-(di-t-butyl)ferrocene,and1-(P,P-adamantyl-t-butyl-phosphinomethyl)-2-(di-hexahydro-pyrimidin-2-yl-phosphinomethyl)-4-t-butylferrocene.20. A process for the carbonylation of ethylenically unsaturatedcompounds comprising reacting said compound with carbon monoxide in thepresence of a source of hydroxyl groups, optionally, a source of anionsand of a catalyst system, the catalyst system obtainable by combining:(a) a metal of Group 8, 9 or 10 of the Periodic Table or a compoundthereof; and (b) the bidentate ligand of formula (I) according toclaim
 1. 21. A process for the carbonylation of ethylenicallyunsaturated compounds as claimed in claim 20, wherein the catalystsystem has a pKa in aqueous solution at 18° C. of between −2 and
 6. 22.A process for the carbonylation of ethylenically unsaturated compoundsas claimed in claim 20, wherein the catalyst system has a pKa in aqueoussolution at 18° C. of between 0 and
 5. 23. The process for using thebidentate ligand according to claim 20 wherein A and B are methylene.24. A novel complex comprising the bidentate ligand of formula Iaccording to claim 1 coordinated to a metal of Group 8, 9 or 10 of thePeriodic Table or a compound thereof.
 25. A catalyst system forcatalysing the carbonylation of an ethylenically unsaturated compound,the system is obtainable by combining: a) a metal of Group 8, 9 or 10 ofthe Periodic Table or a compound thereof, b) the bidentate ligand offormula I according to claim 1, and c) optionally, an acid.
 26. Thecatalyst system according to claim 25, wherein said acid has a pKameasured in dilute aqueous solution at 18° C. of between −2 and
 6. 27.The catalyst system according to claim 25, wherein said acid has a pKameasured in dilute aqueous solution at 18° C. of between 0 and 5.